Contact Author If you are trying to get pregnant or even if you just think there is a chance you might be pregnant after having unprotected sex , and you are wondering about the earliest date that you can take a pregnancy test, then there are a number of factors that you need to take into account before you can decide the answer to this.
Firstly, if your period is already a week late, then you can already take any of the home pregnancy tests that are on the market.
You should get an accurate result. I say you "should get"' because obviously there are always exceptions to the rule, and it may depend on how regular your cycles are. The reason most doctors and sources, including AmericanPregnancy.
HCG is only present in the body when you're pregnant, and that's what most tests test for. Also, you really need to have regular periods to know when your period is a week late! So let's look at the factors you need to take into account. If you are monitoring your cycles because you are trying to get pregnant, then you may well know the answer to this question—but if you are not necessarily trying to get pregnant or just not trying and not preventing, then you may well not be aware of when you ovulated.
If you do not know when you ovulated, then you can calculate your estimated ovulation date using your period —although it may not be that accurate! If you have regular-length cycles, then it is reasonably common to ovulate 14 days before the first day of your period, so you could take that as a rough guess.
So if you think that your period is due on the 20th of the month, then the most common time of ovulation would be around the 6th of the month. If this sounds a bit confusing and overwhelming, FirstResponse who produces one of the most sensitive and accurate pregnancy tests made this handy calculator that helps you estimate when you may have gotten pregnant.
Can and should are two very different verbs here. You can take a test whenever you like. However, if you want accurate results, it's best to take the test at least eight days after you've ovulated.
Waiting until 14 days after ovulation is a much better time frame. That means that taking a test immediately after sex won't give you any viable results. Here's why you want to wait: Pregnancy doesn't start the moment after you have sex. It can take up to six days for the sperm and egg to join. According to this study by J.
Clin Med Res , "[o]ne of the possible outcomes of the pregnancy test is a biochemical pregnancy; where the initial pregnancy test is positive but does not progress into a clinical pregnancy. Not all tests are created equal. Some are much more sensitive meaning they can register lower amounts of hCG than others. So, you potentially will get a false positive if you use an insensitive test early when your body hasn't had time to build up hCG.
Waiting reduces the chances of this—but doesn't eliminate the chances entirely. FirstResponse seems to be the most sensitive according to many clinical tests, including Clin Chem Lab Med's study of the product's efficacy. There are different pregnancy tests available that pick up the pregnancy hormone, hCG, at different strengths. The most sensitive test picks up hCG levels of about 10 in your urine. Other tests pick up hCG at levels of 20, 25 or So the higher the level of hCG is picked up by the tests, the later you will be able to use that test as the hCG builds up in your system.
That said, not all tests are created equal. Everyone on a forum I used to frequent would recommend these test strips because they were so cheap, showed a positive test pretty early on, and were really sensitive 10mlU.
For some reason though, they didn't seem to sell these ones in the shops. They only seemed to be available online, so I would stock up on them so I could use them the next month. The cheapest ones I could find in the shops were much more expensive than these, so it was worth ordering them online.
I also learned somewhere along the way that these are the ones that are used by doctors and hospitals. I don't know how true this is, as I don't have any evidence to prove this. So, the question is, how soon can you use each type of pregnancy test strip? Well, your body would have had to built up certain levels of hCG for the test to show a positive line. The standard levels of hCG differ according to where you look, but wikipedia reports the following levels: