Okay i had sex with two different guys in a row.. i had sex with a guy a on october 18th, and then i had sex with guy B on the 19th and 20th, Guy A he pulled out and i knew for a fact he did. but guy B i dont think he pulled out, every time i get a ultrasound back it says july 12th and i calculates it and it all points back to october 20th with guy B. when my mom had my older sister she had the same due date as me and she said she know for a fact she got pregnant october 20th, but idk is it guy b or guy A, i always calculate when i concept and its always the day i had sex with guy b, and the earliest due ultrasound i had was 12 weeks and it was july 12th and it always say that conception was october 20th and thats with guy b, me and guy A had sex plenty a times and we pulled out & i never got pregnant. are ultrasounds conception dates accurate.. Would Guy B most likely be the father?