accuracy of ultrasounds

I've recently found out that i was pregnant.  After going to the doctor, I had my first ultrasound and he told me i was 10 weeks to the day! Which means my conception date would have been October 18th, if the ultrasound was 100 percent accurate. My delema is that on december 11th I had intercourse with someone, who claimed to have used a condom, but i do not believe he did so. but on the 13th and 14th i had intercourse with a different person.  My last menstrual cycle started around 5th or 6th and ended on the 10th, i have a normal 28 day menstrual cycle.  What I was wondering is in my case, what's more likely or is it possible to tell, which man is the father.  I know sperm can live up to 6 days in the vagina so that ultimately could rule out father one.  But I was wondering if there's a way of telling or if the ultrasound should be consolation enough.  Im just really confused and would like some consolation on trying to track down who the father is.  Should I get a pre-natal dna test?  

[Van73]

Nothing is 100% but the EARLY ultrasound is the most accurate.  When the dr says you are 10 weeks, it means you are 10 weeks but the baby is really 8 weeks gestation.  They count the 2 weeks prior.  A really good website that explains all this is: http://www.baby2see.com/

The best way to know who the REAL father is through a DNA test after the baby is born.

[dbestone]

the early u/s are usually the ones that determine the most accurate weeks of pregnancy. but you mention that the dillemma comes because your not sure which guy that you slept with in Dec, could be the father. i dont see how the 2 men could be in question if according to the u/s your 10 weeks along. meaning you got pregnant in Oct. maybe you made a mistake by typing Dec, but if you didnt, i would rule them both out because you were already pregnant when you slept with them. and if Oct, is what you meant to say, then the dates are mighty close, and the only thing that would 100% tell you the correct father would be a dna. good luck!

[baby8313]

I did mean October lol sorry, it would have been totally rediculous to worry about someone in December! lol Anywoo, I Dont know who the father is, it is completely close, and I wouldnt want to have the child if it were the first mans baby, I dont even know him.  I just dont know what to do or what to think.  

[peekawho]

You really can't get a prenatal dna test.  

Ask about it, but I don't believe you will find anyone who will do it.  

[sarahlou1989]

hi,
i had my period on the 1st of october for 5 days i then missed one of my pills and i came back on on the 12th for 3 days. i am in a relationship but then i slept with my ex on the 18th oct...i dont now how far gone i am yet as i havnt yet had a scan. but who would the father be if my 2nd period didnt happen. and who wud it be if they both did happen? just confused weather the second period was a real period

[peekawho]

If you slept with 2 men in a relatively close time frame, then you'll need a DNA test to determine paternity.

If you had a normal, regular menstrual period on Oct1-5, then missed a pill or two later, that would be a possible reason why you had more bleeding shortly thereafter.  It isn't really another period, its just bleeding.

Its not a good idea to try to "guess" at paternity.  If you aren't sure, you'll need a test.