Conception and Pregnancy

Patient: I feel quit embarssed i have made a mistake, me and my boyfriend split up i had unprotected sex with another guy on the 18th of August he pulled out. I got back with my current boyfriend Aug 23rd I had an ultrasound done at 6 weeks four days it my conception date at 27 of August. & They calculated my lpm as August 13. I am due May 20. I need help.EDIT:I really want it to be my boyfriends.EDIT:I really want it to be my boyfriends.

Symptoms: Conception dates

Doctor: Hello,thanks for contacting askthedoctor.comIf your LMP was august 13th, then by 18th , you were in your safe per iod and ovulation had not occurred by then so chances of you getting pregnant with your boyfriend is low.however on your second encounter you were in your fertile period and even though withdrawal method may have been used but the precum may have gotten inside and possibly impregnated you. As you are pregnant now , the best way to confirm the paternity is with the choroc villous sampling of the fetus for DNA PCR , which can ascertain paternity for sure.I am afraid the paternity looks more in favour of your second encounter.I hope i have answered your query in detail,wishing you good health,regards