who is my daughters father?

My LMP was 11/24/2008. I had sex with one gentleman dec 9,10,or 11th? Then had sex with another gentleman Dec 19th. Who is more probable to be my daughters father? My ultrasounds and conception dates time add up the the 1st guy. I missed my period in dec, but didnt determine i was pregnant until late january. My daughter was 13w and 1 day the first ultrasound, and 21w and 4 days her 2nd ultrasound. Back tracking both of these time periods come back to the 2nd week in dec, which is when i had sex with the 1st guy. I am so confused because me and the first guy live like 4 hours apart now. we took 2 mail-in dna tests. which both came back negative, with this news i was in shock! It doesnt make sense to me, can someone help me make sense of it?? Please.

[AnnieBrooke]

The dates lead to the first guy, but since the two candidates are only 10 days apart, it could be either one.  If the DNA tests were on the up and up, and came back negative for the first guy, the dates don't matter.  (Unless he cheated and used DNA from a buddy.)  I would test with the second guy, and if his DNA also does not match, get an attorney involved in the town where the other guy lives and get a certified DNA test from him.