You shouldnt be made to feel guilty, even if he hasnt cheated, theres something or someone telling you that he has, and thats pretty stressful in itself. Ive been through it a few times hun, Ive had to fight for my boyfriend on one occasion when he met a girl from cornwall (half way down the country from me) and ended our relationship 18 month for this girl, he'd known 2 days! I fought, and I fought hard, he came running back. But my god, the pain and the stress, I didnt know if he was worth it at the time!!
But thats your babies father, if hes cheating, he doesnt deserve you or your little one.
I know its hard what to believe, but dont let him, no matter what he does, turn it back on you. Your the innocent party in the situation xx