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.


Last modified: May 31, 2014