QuestionI had sex with a girlfriend on March 17, 2010. A the time, she was living with another man with whom she was having regular sexual relations. She became pregnant and had an ultrasound on June 17 which stated she was 12 weeks 4 days pregnant, and then on August 10 stating she was 20 weeks 2 days pregnant. After both ultrasounds, the doctor gave her a due date of December 26. Is it possible she became pregant from out March 17 sexual encounter?
AnswerHello,
Based on the information I have right now, it seems unlikely that your sexual encounter resulted in this pregnancy. The ultrasound itself gives an estimated conception date of April 4th, 2010 and with that due date gives a range of possible conception dates from March 28th to April 4th, 2010. I'm going to explain ultrasound and dating and this might be a little confusing at first but hopefully I can write this well enough to understand :
The ultrasound gestational age does not go by conception date, but from the estimated last menstrual period. (Typical menstrual cycles are 28 - 30 days, with the release of the egg on day 14). So once a woman actually conceives she is already considered 2 weeks pregnant. Even though sperm and egg just recently united. So with her first ultrasound on June 17th at 12 weeks and 4 days, she conceived the baby 10 weeks and 4 days before. If a woman has irregular cycles (not the typical amount of days) or does not remember it, an early ultrasound helps to determine how far along she is (and for those who need it, an estimated conception date)
Keep in mind these are estimations but in my opinion March 17th is far off enough that it seems unlikely this pregnancy came from that sexual encounter, however I do have to throw it out there and mention that if there is a question of paternity, a paternity test should be done to be 100% sure.
I hope this helps. Take care
