I had sex with my ex on October 15th after that I saw a little spotting so the next day on the 16 I went to the doctor to see why I started spotting because it had got heavier. My doctor told me that it was just my period starting, surely enough I bled that whole week and it was my period. Anyway I had sex with my first on the night of october 27th my period had been long over, I went back to the doctor on november 6th and she told me my urine test was positive but it was a little faint line and that I should re test in a few days. I got a blood test and an ultrasound sound done they told me it was too early to see anything I went back at 8 weeks and they told Me that since I had a period on the week of the 15th and the ultrasound determined my due date would be july 22nd this means it is my first baby and not my ex. I want this to be my first baby, in 25 weeks along now which is still in accordance with the july 22nd due date so should I be worried that it is not my first baby?