Who do you think is most likely the father?

i had my period December 13th or 14th of December. and the doctor put me on clomid to ovulate. im 32 weeks and 4 days pregnant today according to my last menstrual cycle and my due sate is Sept 19th. I had with my ex boyfriend unprotected December 20th & 26th..we broke up and i slept with my guy friend ive known for years on December 29th(stupid i know) but 9 hours after we had i took the morning after pill. that day i felt cramping and i took an OVULATION test and it was positive. so i was either ovulating or about to ovulate. i took a pregnancy test January 8th and it was negative and on January 12th i took another test and it was a faint positive. The sonogram measurements he is measuring 34 weeks and 4 days..that would move my conception date back further..which would make more sense...since the morning after pill failed..But some people say don't go by the sonogram measurements because the baby grows at different rates but the past few sonograms ive been 1+ week farther along..so what do you think?