My boyfriend got a text from a girl at 3 am: Thoughts?

So my boyfriend and I are expecting our second baby well last night he went to a friends place and before he went he came home showered and fell asleep on the couch he asked if he could go before hand he always asks and I know these friends but they still have so many people there anyways he left at 7 and says he was home by 3:30 am well he came in and slept on the couch instead of coming to bed I thought his phone was dead so I plugged it in and it was charged still but on the main screen it showed a text from a girl so I looked well the top half is deleted but it was her asking if something was somewhere but it didn’t say what he replied well I asked him and was like why is this person messaging you and what’s she looking for half the convo was deleted but he said she was looking for her jacket so I was like did u drive her home he’s like no I slept on buddies couch and she stayed there I feel I’m going crazy because if it was innocent why is half it deleted I feel he’s hiding something but I have no proof and these friends wouldn’t tell me if something happen he said he got home at 3:30 this message from her came in at 3:37 am I over reacting I didn’t even know he talked to this girl or was friends with her enough to text