i need a professionals help/opinion about conceiving dates

Kaykay
So my last period was 10/08-10-12 I had sex with guy A On 10/11 when your period is going away and it's brown. And I have sex with guy B on 10/12,10/15,10/21,10/22,10/23,10/26 ..I am 28weeks and 3 days, and my due date is 07/15/2017.... is it possible to get pregnant on the last couple days of your period?? Who do u think the dad is?