In general, women can only conceive when they are ovulating-that is, when their ovaries
release a new egg into their fallopian tubes for fertilization. Ovulation typically occurs about two weeks after the start of your menstrual period, however, there is a LOT of variation among women. Most women are completely unaware when they are ovulating. Without specialized testing around your fertile time, trying to determine when conception occurred based on your menstrual cycle is unreliable.

Trying to figure out which day you conceived based on when you had sexual intercourse can be challenging. It’s usually not possible to determine the exact day you ovulated and the egg is only available for fertilization one day. Conception is a process that takes time, and a man’s sperm can actually stay alive inside your body for several days after vaginal intercourse. This can make it difficult to determine when you conceived, especially if you had more than one male partner during the time when you ovulated. Also, remember that you could become pregnant even if you or your partner used birth control, since no method of birth control is 100% effective at preventing pregnancy.

The best way to find out if you are pregnant for sure is with a pregnancy confirmation ultrasound. A pregnancy confirmation ultrasound can help you determine an approximate age of your growing baby. The earlier in pregnancy that this ultrasound is performed, the more accurate the measurements will be, but it will not be able to pinpoint the day you conceived. If you had sex with two different people around your fertile time, paternity testing during your pregnancy, or after delivery, is the only way to know the identity of the father with certainty.

If you are interested in receiving a free pregnancy confirmation ultrasound, please call 866-406-9327 and we will refer you to a local pregnancy center that offers this free and confidential service. Learn more with our online quiz.