Thank you for your question and I recommend you discuss it with your doctor
. In general, pregnancy tests are accurate near or at about the time that you would normally have had your usual menstrual cycle bleeding
. This will obviously vary from person to person, but the key is that pregnancy tests are not as effective when used either too soon or too late, as the hormone that they measure is elevated especially during these early stages of pregnancy. There are many ways to calculate your anticipated or expected date of conception, and most of these will rely on your last menstrual period. If you are irregular or are using hormonal contraception
that affects the date of your normal cycle, then this could play a role in the efficacy and exactness of using any of these methods. Another way to tell when you conceived is by using an ultrasound, which your doctor is able to use with some certainty. While it is not exact, these can give a relatively good idea of conception as well. Interestingly, the sooner that they are used, the more effective that they can be at determining the age of the fetus. There are many things that should be done to help answer your questions at this point, so please speak with your doctor.