Paternity Uncertainty During Pregnancy: Understanding Potential Fathers

Question
I am 33 wks pregnant and as the time gets nearer for me to deliver i am afraid of who the father might be. My last period was sept 5 2008 and i had sex on the 12th and 13th with one guy and on the 19th with my current boyfriend. My cycle varies from 26 days to 28 and i'm not sure who it could be. I spotted on the 1st of oct and just really want to have peace of mind for me an him because i know its hard for him to deal with and i have done research on my own and learn sperm can last waiting for an egg 2-3 days but can last 7. please help me!!!!

Answer
Dear Rebecca,

According to the dates you have given me, I calculate your estimated conception date to have been 9/19/08. This gives you an estimated due date of 6/12/09. I would assume you would have had an ultrasound to confirm dating of the pregnancy sometime before the 12th week of pregnancy. If so, that dating would be considered most accurate.

Unprotected sex which takes place within 5 days of ovulation carries with it the highest risk of conception. This is because sperm cells can survive for a maximum of five days under ideal conditions once past the cervix. They just swim around trying to find a viable egg to fertilize until they die. But five days would essentially be the maximum and that would be under the most ideal conditions.

My best guess would be that the most likely date of conception would have been on/about 9/19. I hope this has helped you and answered your question. I wish you well.

Brenda