conception confusion

My boyfriend and I broke up for two weeks in January. On Jan 14 I had sex with a close friend but he did not ejaculate inside me. On January 17th I started my normal period and it was the same as always. I got back together with my boyfriend on Jan 20 and we had unprotected sex quite a bit. Going by my due date of Oct 24th, conception calculators that I have used say date of conception was between jan.29th and Feb 6th. I know the dates don't match up as it being the friends baby but my question is even though I had my regular 5 day normal period, could it be my friends?