paternity

I have irregular periods. They are usually every 36-37 days apart except in Jan (47 days) and June (43 days). My last known cycle was on 6/29 and i truly believe I had a period on 8/3/09. I had unprotected sex on 8/6/09 with guy # 1 ( we did ust the w/d method but I know that is not foulproof) and my ex and i decided to get back together after that so we were together from 8/14 and beyond. I took a hpt test on 8/29/09 becuase of my irregular cycles it was neg but I got a postive reading on 9/20/09. I went to the doc on 10/8/09 and they said i was 9 weeks and 5 days. So would guy # 1 be the father or is it the current guy. I had an transviginial us and they said my due date is 5/10/10

[Elaine Brown, MD]

Hi!
All the data point to your ex-ex-boyfriend as the father.  Your due date of 5/10 puts your conception date on 8/17.  If you did have a period on 8/3--it would have been too early to conceive on 8/6. But I would also wonder whether you might still have been menstruating at that time.  The only way to know for sure is to do a paternity test.  Those cost approximately $1000.  It is usually best to wait until the baby is born and use the umbilical cord blood for the analysis.  The guy(s) can do a buccal swab in some cases.
Congratulations on your pregnancy.  I hope you end up with the guy who is right for you and junior regardless of the DNA!
Good luck!
Dr B