Paternity Testing: Understanding Potential Fathers & Pregnancy Timeline

Question
I know this sounds bad but I really need your help. I'm pregnant, My last period was August 25th , I slept with two people, I really need to know who the father is I had sex with guy (A) on September 1st and i slept with guy (B) on September 10th and the 14th, I was using a ovulation kit everyday after my period and I got a positive sign on the 10th when i tested that morning, so I'm guessing I  ovulated on the 10th is it possible that I can be pregnant from guy (A)? on October 9th I had a ultrasound done and the doctor told me that I was 6 weeks pregnant and 6 days it that right or could it be wrong?

Answer
Pat,
Yes it is possible. I actually would have guessed it was guy A to begin with because it was on day 7 of your cycle. If however, your ovulation kit said it was positive on the 10th, then I would go by that. The only true way to be 100% sure is with a paternity test. Good luck!