What kind of timeframe has all of this occurred? I have to agree that choosing to have sex would suggest you stick with it, IF (big IF) it is your kid. No doubt I'd be having a parent test, during the pregnancy if possible. If it's yours, that's the prize you won. If it's not, then your decision to leave seems pretty cut and dry. Your son will understand that decision later in life for sure. God works in mysterious ways, if you believe in that sort of thing. To me the parental test would be my sign from God, however that turns out.
Good luck. God bless.
Me: 37, W: 36 S6, S3 M: 8 T:11 Discovered 1st A: 9/3/14 Began DB: 9/20/14 W "ended" 1st A repeatedly Discovered at least 3 more A's, filed 10/29/14