How to determine the date of conception?
Patient: i m pregnant but i don t have regular periods i know my last one was on november the 21 oh the 28 and it was not normal it was brown color for 2 days only. i have sex with my husband everyday from november to december the 6 or 7 then he was gone i had sex with this other guy on december the 15, 16,and 17....the doctors say they are going to go with my baby measurements so i m 19 weeks going to 20 weeks on saturday i really want to know when is the day i got pregnant Doctor: Hallow Dear,It is not clear from your history whether you had your last menstrual period (LMP) on 21 or 28 November or from 21st through 28th of November. I will presume your LMP to be 21 November for the current calculations. Also I am presuming your menses to be regular coming after every 30 days. If there are any changes in this, you may then make the modification in the calculations. Egg is released (ovulation) from the ovaries 14 days prior to the next menses. Your expected menstruation would be on 21 December; hence the expected date of ovulation would be 7 December. The egg has life of 24 hours. Hence any sexual intercourse around 6-7 December would be responsible for the pregnancy. Since, it is not clear on which date the baby was 19weeks, it would not be possible to make any calculations based on that. With the available history, it seems you are carrying the child of your husband. If you still have any doubt, the final confirmation can be done by DNA test after the delivery of the baby. I hope this helps you.