Anonymous asked in Pregnancy & ParentingPregnancy · 1 decade ago

pregnancy test?

How long after I've had sex is the best time to take an at-home pregnancy test?

9 Answers

  • Favorite Answer

    How soon can I test? Well, first you gotta know how the test works. Briefly: the home pregnancy test (HPT) works by detecting a hormone called human chorionic gonadotropin (hCG.) When an egg is fertilized, it takes about 6 to 12 days to implant in the uterus, and then it begins to secrete hCG. It takes another day or two for enough hCG to build up and make its way into your pee. So, generally speaking, the earliest you can expect a positive HPT is 8 days past ovulation ("DPO") and the latest would be about 16 DPO. It is possible to get a positive test earlier or later, but not as common. In my experience, if you use a sensitive "early" test (anything that detects 25 mIU/mL of hCG or less) you can test around 12-14 DPO and feel reasonably secure with your results (the later you test, the more secure you can feel in its accuracy.)

    If you do not chart or monitor your fertility in any way, and you think you may have conceived, you should wait 19 days (or longer) after having sex to test. Why 19?! Sperm can live approximately 5 days in the proper environment; if the sperm managed to live until you popped an egg, the actual conception could have taken place several days after the sex act that got the sperm there. To make sure you're not testing too early, assume the sperm had very long lives (5 days is considered a very long sperm life) and that conception occurred then. Then allow 14 days for the embryo to implant and develop enough hCG to show up on a pregnancy test (96% of pregnant women will test positive by then.)

    Note: some HPT's say "test 5 days before your period is due!" or some such thing. Please note they are assuming a textbook 28-day cycle, with ovulation on Day 14. "5 days before your period is due" thus really "translates" to 10 DPO.

    Essentially, you should remember that your high school biology textbook was WRONG. NOT all women have 28-day cycles and NOT all women ovulate on Day 14. For more info on this type of thing, see the Fertility Info section.

    Here's an example. This is the textbook-perfect 28-day cycle with ovulation occurring on day 14 (in pink.) 10 DPO and later are reasonable days for testing (in green.) This is the cycle the HPT companies have in mind when they say "test 5 days before your period is due!"

    Well, not everyone's body works this way. Here's another 28-day cycle-- but this one has ovulation occurring a little bit later, still well within the normal range. Watch what happens to your (green) testing opportunities!

    All of a sudden, "5 days before your period is due!" is way too early for you to expect a positive test! (I tend to ovulate later myself, so by the time the "gold standard" of testing at 14 DPO is applicable, my period is already 3 days late! I needed to use an "early detection" test on the first day of my missed period. A "regular" test would probably have been negative-- even though my daughter is living proof that I was, indeed, pregnant ;)

    Of course, it works in reverse, too. If you're an early ovulator, you're lucky! Check it out:

    In this scenario, you could test even sooner than 5 days before your expected period.

    Ultimately, it's important to remember that implantation is a variable thing. You may be able to detect a pregnancy very early on, but then again, you may not! If you can't, don't despair.

    Good luck and Merry Christmas!

    Source(s): ~~ButterFlyAngel~~
  • Pregnancy tests are intended to distinguish a unique hormone that is just present when a lady is pregnant. This hormone, known as human chorionic gonadotropin (HCG), is created by the placenta when a female ovum (egg) has been treated by a male spermatozoa (sperm) and inserts in the female’s uterus. This happens, by and large, around six days after the egg and sperm meet up. The level of HCG increments as the pregnancy advances. Be that as it may, six days is only a normal for a few ladies, implantation does not happen until days after the fact. Pregnancy tests can identify HCG in both pee and blood. While a few ladies like to go to the specialist for a blood test to figure out if they are pregnant, numerous ladies like to perform a pregnancy test in the solace and protection of their own washroom. These tests, accessible monetarily, are extremely exact generally when utilized at the correct time. Home pregnancy tests (HPTs) are most exact when utilized one week after a missed menstrual period. On the other hand, as said already, a few ladies don’t encounter implantation until a later time. These ladies, a littler rate, are undoubtedly pregnant, however their HPT may be negative. This can bring about some disarray and stress.

  • Anonymous
    1 decade ago

    That would depend on at what point in your cycle the sex occurred. I would wait until after you are late then test. If you are to anxious to find out you can test about 2 days before you miss your period with some test. The ones the say they can detect up to 5 days early are only 40% accurate with that.

  • Star
    Lv 5
    1 decade ago

    Some can be done as many as 5 days before your missed period, some day of and some not until 5 days after. It depends on which test you get when you can take it, as for a best time, first thing in the morning.

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  • 1 decade ago

    There are some test like First Response that can tell you a week before your period is due. For accurate results however, wait until your missed period. The longer you wait, the higher your HGC level (pregnancy hormone). If you are pregnant and test too early, you can get a negative result because your HGC level is too low. I recommend waiting until your missed period.

  • 1 decade ago

    You should wait at least 5 days before your missed period. So if you had sex lastnight but you aren't supposed to start your next menstrual cycle for another 10 days, then you would wait 5 more days. As long as your being sexually active I always advice women to use protection or at least birth control (if you are not wanting to become pregnant). Good luck!!

  • 1 decade ago

    if you are deathly afraid of the consequences, wait only some seven months and if your period wouldn't appear, take the test right away.

  • Anonymous
    1 decade ago

    14 days to get a reliable result.

  • Anonymous
    1 decade ago

    after you missed your period 3 weeks later usually

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