I feel like shit

I was sleeping with two guys. One was everyday and he came in me many times. And then I was with one guy Oct 15th, he didn’t cum inside of me and it was that one time. My last period was Sept 22nd-sept 26th. I had a positive pregnancy test the week of my missed period.

Based on the dates its impossible for it to be the guy who I had intercourse with Oct 15th no? I am about 6 weeks give or take a day or two.