Cheating

I’m currently 21 weeks pregnant, my boyfriend and I have been together for almost two years. We’ve had a lot of problems but learned to work through them and he’s grown so much into a great supportive boyfriend. Well since January we haven’t lived together, but have spent almost everyday with each other. On mother’s day of this year i went through his phone. ( not sure why, i never do, he’s never given be a reason not to trust him, i just had this sudden urge) well i saw an email account that ive never seen him use before so i went on it and looked through. He had been talking to several people sexually since about the beginning of April, about meet ups and receiving and sending pictures and what not, he swears he never met up with anyone or did anything physical at all, and he said he was just curious and being stupid.

I’m not sure what to do, i love this guy, we have a baby on the way, and i’m the over forgiving type of person, i make excuses for everyone and their actions so of course i’ve already made every excuse.

My question is, do you think it’s possible between him seeing a therapist and is seeing a couples therapist for us to work out. Do you think people can only make a mistake like this once?