<human>: Hi I need help determining my babys father! My last menstrual period was August 20, 2010 I slept with my boyfriend August 13,14,15, & 26th. i slept with my ex sept 5 & 11th. i went to the doctor on october 8th and had an ultrasound & she said i was 7 weeks. i got to hear the heatbeat and everything. Im still confused though on who the father might be, please help!
<bot>: Hi, Your ex is the father of your baby. First trimester ultrasounds are very accurate in estimating gestational age with an error of just 1 week. You would have had to have conceived 5 weeks before 8 October, to be 7 weeks on 8th October. This is because we always time the pregnancy not from day of conception but the last menstrual period. So the confusion of 2 weeks, as those two weeks represent the follicular phase of the cycle you conceived in. Hope this helps. Regards.