Confused

So I just started seeing this guy and he's great. He's a single dad and fought for custody of his son, he has a great job and is very caring. The problem is, or not, is that he worked last night and said he was to tired to do anything with me but then at about midnight he posted being at a bar listening to music. Not sure if he was with someon or not, I have asked him if he's seeing someone else and he's said no. What am I supposed to think after seeing that. I also stated in the beginning to be completely honest cuz I don't like liars!!! Am I overreacting?