Dont think i'm pregnant WITH MY HUSBAND.?

I'm in a bit of a fix n i need your help by next Wednsday. Im a 38yr old fmale. Basically, i dont think i'm marrying the right guy. Hes in remission from a serious life threatening illness at the moment. His wife died 2yrs ago. He always wanted kids. I really like him, he offers me alot of security and i'm going to inherit the lot when he pes. However, I'm in the family way. He thinks this kids his and has actually cried with joy. Hes real sloppy. The thing is....I dont reckon hes the dad. Around that time, he was in hospital and i was very lonely home alone. I slept with 3 old friends of mine, and i'm nearly sure its one of theirs as we were not careful. Jeeze, what do i do? I mean, i dont wanta mess up my life? The other 3 guys, none of them would offer me the security this guy does and they are kinda waste of space dudes, never worked adn ones struggling with addiciton issues. So i dont need that hle. What will i do