Hello, i hope you can help me i am currently from what an early Ultrasound detected 10-11 weeks pregnant with my first child. I was happy until i realised the conception date which was around 10th September. I was only with one partner at that time. But around the beginning of August say around 5th-10th August i did have intercourse with somebody else. I of course want the father to be with whome i am currently with as i have told him it was his. So my question is how wrong can a conception date be? Could my baby be the first guys? I had my ultrasound at 5 weeks 6 days.