is he cheating on me?

my boyfriend and I have stopped having sex lately and he has been so weird. I know I shouldn't of but I read his texts while he was sleeping. and I saw multiple girls with texts saying "we can Monday baby" "I'll come over next Tuesday" and he told me he was going camping with his friends from Monday to Thursday. what do I do? I love him so much but I don't want to say anything because I'm the one who read his texts! and don't know if I can say he's cheating on me because he hasn't done anything yet he's just planned on it! someone help :(