Cheating???

I went on my boyfriends phone this weekend w out him knowing we are in a long distance relationship and he’s in college. Before we started dating he talked to a bunch of girls and was a fuck boy so to speak. I also found nudes on his phone awhile ago but he claims they were they were on there before we were dating and this was on an old phone. I found a girls name on his phone they go to college together and I noticed he had silenced the notifications. In the messages I found him talking about how he had a migraine and how he needed to sleep it off and how they both chew and I asked him about it. I asked him about it and he got defensive and said i don’t trust and he said she is a friend from college and asked why can’t he have friends of the opposite sex. We have been together for almost two years. I texted him today and asked wyd and he said at school and than I asked him to reply to me and he said no I had to run home to grab something and his mom packs his lunch so I know he didn’t go to eat lunch and his house is about 20-25 min away from his college and he only has an hour lunch. Do you think he was with her? He also told his best friend about her and asked him if he should tell me about her. I really don’t think he would drive that far to get something so irrelevant I truly don’t think he went home but why would he lie?