When Does a Pregnancy Test Turn Positive?


Along your journey to parenthood one of the hardest times is what is affectionately known as the ‘two week wait’. This is the two weeks between when you tried to conceive, to the time when you can finally test and get an accurate pregnancy test result.

Unfortunately, pregnancy tests do not run on magic – you cannot take one the morning after you had sex and assume that it will be positive, or negative.

How a Pregnancy Test Works:

In order for a home pregnancy test to show a positive result, something special needs to happen – an egg has to first be fertilized and then it has to implant itself in the uterus. Once this occurs, the pregnancy hormone hCG will begin to be secreted into the body.

A home pregnancy test analyzes your urine to see if there is any hCG (human chorionic gonadotropin) present.


Types of Pregnancy Tests

The two most common methods of testing for pregnancy are Blood Pregnancy Tests and Home Pregnancy Urine Tests. Both test for hCG levels; the only difference lies in that the former tests its levels within the blood stream while the later in the urine.

A positive blood test will usually show a positive result 3 to 4 days after implantation, or roughly 9 to 10 days after ovulation.

For a home urine test, however, a positive result will not be visible until a week after implantation or until you have a missed period. Do not buy into the myth that certain urine tests can give a positive result before you have missed your period. In actuality, only 25 percent of pregnant women will receive a positive home pregnancy test 2 days before they have missed their period. Approximately 40 percent of pregnant women will receive a positive test result the day before they have a missed period. On average, it will take at least 13 days after ovulation for a urine test to first turn positive.

Factors To Consider

Several factors may affect the time it takes for a pregnancy test to first show a positive result. These include the date of ovulation, date of implantation, hCG levels in either the blood stream or urine, and the sensitivity of the test. The date of ovulation is of great significance in calculating when a pregnancy test might first show a positive result, because it signifies that ovulation occurred and fertilization took place. The amount of time either this process, or the process of implantation, may take will differ between women. Therefore, though one woman’s pregnancy test may show positive today, another’s may only become positive a day or two later even if they were to have conceived on the same day.

The hCG levels in the urine and in the blood vary greatly as to the definition of what is ‘normal’ or ‘high’ and this affects how early a pregnancy can be identified. Though you may be pregnant, if you have a low hCG level you will receive a negative result, and it would take a few days for it to become positive. However, if your levels of hCG are at a high level, the blood or urine test will instantaneously show a positive. Also varied is the concentration of urine levels throughout the course of the day. This is why it is recommended that a home urine pregnancy test be done with first morning urine, when urine concentration is at its highest.

Pregnancy tests also vary in sensitivity. Low sensitivity tests tend to detect pregnancy earlier than highly sensitive ones. Pregnancy test sensitivities are indicated in mIU/ml, therefore a test with a sensitivity of 40 mIU/ml will require twice the amount of HCG than that of a test which has a sensitivity of just 20 mIU/ml.

  • SR

    QUESTION: I have taken 3 pregnancy tests, all were negative. My period was due May 10 and here we are at May 30 and still no period. I do have sore breasts and and am more moody than usual but I still have no period. What should I do.

  • http://www.babyhopes.com/ Vickie B.

    At this point, you should go see a doctor to get a blood test.

  • JJW

    I received a period 2 days before it was suppose to come on and it only lasted 3 days. My breasts are sore, I’m having some stomach pain and I’m constantly feeling nauseated but all the pregnancy test say negative.. What should I do?

  • http://www.babyhopes.com/ Vickie B.

    You should probably go to your doctor so they can pinpoint what your symptoms are indicative of.

  • jo

    I took a clearblue test yesterday and it was positive then took two more and they were negative. This is my fifth pregnancy and hasn’t happened before, I don’t know which one to believe

  • Nyomiie21

    Try another CB digital test today and depending on what it says book an appointment with your doctor :) hope alls ok at you get the result you want! Fingers crossed for u. Best of luck :) x

  • jo

    Thanks I will I have been feeling sick, I think the first picked it up and the others didn’t detect it maybe because it’s too early, thanks fingers crossed

  • chelsee

    ok so I went to the hospital several times for the same symptoms : nausea , ovarian pain , frequent urination etc.. and happen to look at the papers and I looked at the blood tests they ran & it said my hCg level was a 10 !! like Im so confused !! and im still having all the symptoms and there are new 1’s starting !! such as im very moody , a lot of smells make feel like im going to be sick !! what does that mean ?

  • http://www.babyhopes.com/ Vickie B.

    Unfortunately, we aren’t doctors here so we can’t interpret what that could mean. You might want to call the doctor and ask to speak to a nurse. She may be able to help you figure it out.

  • excited!!

    I tested my blood serum at work. The test came out positive but it took about fifteen minutes to turn. Is that accurate since it took so long to turn positive.

  • Hmmm???

    I spotted the whole week prior to my scheduled period and have not felt right. Although my period also started, I still just do not feel right. I have taken several tests, all negative. Very confused.

  • http://www.babyhopes.com/ Vickie B.

    Maybe you should see your doctor and get checked out to see if there is something going on with your hormones that could be making you feel this way.

  • mrs warner

    I may have pcos since i had irregular periods. However i lost weight and it became regulated. Been ttc to conceive. Had intercourse on my fertile days according to the ovulation calendar now i am 15 with out a flow. Should i test?

  • http://www.babyhopes.com/ Vickie B.

    Did you use ovulation predictor tests to determine that you actually ovulated? I don’t understand what you mean that you are 15?

  • Roxanne

    I’m 16 had my period last on the 27/08/14 just came off the pills to have my period now I decided not to take the pills anymore. Before starting to take the pills I had a 25 days cycle my period is only 2 days long. Took 5 home pg tests all neg, only 1 day left in this month still no period PLEASE HELP!

  • http://www.babyhopes.com/ Vickie B.

    It could take a while for your body to return to normal after you stop taking hormonal birth control. You might want to talk to the doctor to see how long it typically takes for your period to return to normal after stopping the pill.

  • Auleilei

    My last period was on august 26 started my period 4days late on september 30 then it lasted 2days and i still have cramps. When should i take a prego test

  • http://www.babyhopes.com/ Vickie B.

    Actually now would be an okay time to take a pregnancy test..

  • daysha

    My last period was in Aug 15 and my period didn’t come for Sept nd its now October 07 with pregnancy sign and I took a PT early nd it said negative what should I do nd need help nd Ihave more to say

  • http://www.babyhopes.com/ Vickie B.

    If the tests are negative, you might want to visit your doctor to find out why your period is missing. There may be a medical reason, like PCOS, that might be causing the problem.

  • Roxanne

    I went to see my doctor on the 06 of October took a PT and it said negative and as I posted before my last period was the 27 of August. The doctor said I should come back in three weeks time to do another test ,don’t know what to think.

  • http://www.babyhopes.com/ Vickie B.

    Ultimately, until your see your period, you should keep in mind that pregnancy could be possible even with the negative tests. Eat healthily and take care of yourself as if were pregnant. If the period doesn’t arrive by the 3 weeks time period, you might want to demand that the doctor do a scan or blood tests to see if they can figure out why your period stopped.

  • Julie

    I have same my last period was 27 August I was six days early. My period still has not come I took sample to docs and results came back negitive. I am feeling all the symptoms tender breasts, mild cramping, feeling sick and tired! Please advise. Thanks

  • Julie

    Was meant for forum x

  • Kelly

    I took a pt this morning an as soon as I am done before I lay it down it’s says negative.. Is this right? I’m two days late an no signs of period..

  • sydneyrae

    So, I need help.
    My pregnancy test had a faint negative line. Hasnt ever been that faint, you could barely see it, but you could tell it was there, ya know? I’m almost two weeks late, on my period. When should I test again? My periods are regular.

  • http://www.babyhopes.com/ Vickie B.

    You can’t assume you aren’t pregnant by a negative pregnancy test even when your period is already late. Either you need your period to arrive, get a positive pregnancy test or have a doctor perform an ultrasound to definitively know whether or not your are pregnant.

  • http://www.babyhopes.com/ Vickie B.

    You should probably test again now. It almost sounds like you had a defective test if the test line was as light as you say.

  • sona

    Last month I had a brown discharge for 3 days after we tried for a baby (for the first time) and the doctor says its just ovulation blood and there is nothing to worry about!!
    Now in this month my period is already one week late..
    Today I took the PT test and it turned negetive..
    I totally dont have any idea of whats wrong with my period and even I dont know weather I am pregnant or not.. there is even no symptoms of being pregnant!
    Can you tell me whats wrong with me!!?

  • http://www.babyhopes.com/ Vickie B.

    Unfortunately, there are many reasons why your period would be late. http://www.babyhopes.com/articles/periodlate.html If you are really concerned you can talk with your doctor. They should be able to ease your Ming a little.

  • Amy Manovsky

    Ok i had a full period last month this month i had a light period but it was one day early an only lasted 2 or3 days an stoped then i had sex an i spotted but my breast r extremely tender my stomach is cramping an im nauseous through out the day i took a test an it said negitive with my other 2 kids i disnt find out till i was 2 months someone please help me

  • claire

    So I had my period on the 20th of august then when the september one came it wasn’t the right colour it was more browny black and lasted a maximum of 48 hours. I have been having unprotwcted sex. Usually my periods last for 5-7 days. Now there is no sign of the october one either. Ive had 3 negative tests im really tired. I already have a 2 yr old. And my periods have been normal since I started them. Any help will be muchly appreciated.

  • maira

    my ovalution time strart from 30 sep ad get end on 5th oct then i have unprotected sex on 11 oct ,after all i get my period gone missed for this reason i hv take prgnency test on on friday morning in oct , i get my result negative , now its confirm that i m not pregnent pls help soon , i worried

  • mommytobe

    Had my period 9/08 for five days ( normal length) this month on 10/06 I started my “period” that lasted two days the third and fourth day I was spotting brown blood. Nothing that covered a pad or anything . my boyfriend has started having a crave mcdoubles sleeping later than normal and getting tired quicker in the day. While ive been having bad migranes as well as feeling exhausted at work. I did have cramping that came a day before 10/06. But when I’m menstrating cramping lasts days before a period .. Could I be preggo ? And if so, when should I test?

  • http://www.babyhopes.com/ Vickie B.

    Sounds like you need to see your doctor to see about getting an ultrasound scheduled as pregnancy tests don’t typically work for you.

  • http://www.babyhopes.com/ Vickie B.

    Either you are pregnant or you have a hormone imbalance going on. If you are pregnant, you should be coming up to the 2 month mark if you count the sorta period in September as you were already pregnant and you were just having early pregnancy bleeding. If your period doesn’t arrive, you should probably go to your doctor to find out what is going on.

  • http://www.babyhopes.com/ Vickie B.

    So, your period was from Sept. 30 to the 5th of Oct.? You said ovulation in your post but ovulation doesn’t last beyond one day. You had unprotected sex at the right time to get pregnant unfortunately so until your period arrives or your doctor gives you an ultrasound, you can’t rule that out. Sorry for the bad news.

  • http://www.babyhopes.com/ Vickie B.

    If you are pregnant and just had early pregnancy bleeding (the “period” on 10/6) you should be able to test now as you would have gotten pregnant in September. I am not sure if you typed the post right because you’d have a very tuned in boyfriend if he was craving the McDoubles on your behalf :D

  • Dimples5941

    I had a normal period in September. I have a 32 day cycle that lasts 4 days. Usually have a heavy flow/clots/etc. I started my “period” in October 6 days early. It was very light for 2-3 days and then gone. No clots-could have probably worn 1 pad/tampon for the entire thing. I was scheduled to start my period yesterday so I took a pregnancy test today and it was negative. Do you think I could be pregnant but testing too early? It seems as though if what I experienced was implantation bleeding that ended 4 days ago, I would be producing enough hcg to show on a test (25 miu). Thoughts?

  • http://www.babyhopes.com/ Vickie B.

    It really depends on when you started your period in September. If it was implantation bleeding you would need to wait about 10 days after the initial bleeding to test to allow the hcg to build up to levels detectable by pregnancy tests.

  • Sherri Brewer

    Hi I’m a mother of 3 wonderful children. 2 girls ages 5 1/2 yrs & 4 1/2 yrs & a 11 month old boy. My periods have always been on time like clockwork & last 4 days long. 3 months ago my period changed. It went from a red color & 4 days to a brown & 2 1/2 days. 2 months ago same thing so I took a test it was negative. Then when I woke up next morning that same test showed a positive result. Last month my period was a week early brown in color & only 1 1/2 days long. Took another test same thing happened again. Negative result but next morning showed up as a positive result. This month I had my period the 1st it was brown again & lasted only 1 1/2 days then I was in e.r. 4 bowel issues. Urine PT came back negative but blood test stated inconclusive. My next period is due the 29th of October to the 1st of November. I don’t have any insurance right now so I don’t know what to do. Any ideas?

  • heather

    I had my period on September 30th, and only lasted 4 days, I’m not due for my period until the 30th of October, I had what I believe is implantation bleeding 2 days ago I’m just feeling off and was wondering what my chances were for getting pregnant.? I just came off of my birth control a month ago but it had been expired for a year.

Last modified: May 31, 2014