I Had an u/s done on oct.22,2010 sayin i was 7 weeks due date june 10th. This Wouldve meant that i conceieved when i was with my bf sep.17 2010. But i just went to get another ultrasound done and stated that i was 20 weeks and 1 day on jan.17,2010, giving me a due date of june 5th, if you calculate my LMP(aug.29th) this would be accurate for a 28 day cycle but i have a 31 day cycle. I was with someone else on sep.10th once unprotected, but my bf has been getting all the symptoms, nausea, nosebleeds... should i worry or should i just go by the first u/s?