my BF and I have been together for a year in a week. Around when we first started dating (maybe a month and a half) he told me that he was in love / loved this girl that is his best friend from where he grew up. Before he had moved here (6 or so years go) they had hooked up (made out) on one of his last days. 

Over the months I let it go cause he assured me that they weren't a thing or gonna be a thing. She came to visit around Holiday season and he told her that he told me about their hook up and she refused to meet me. (She doesn't know how he feels/felt) I let them visit and do their thing cause his other friend had come and she was mad at him for trying to say that she had to meet me cause we were all supposed to go on a road trip that I had to skip because of work. 

Now months later he is back home visiting for her graduation and her, him, her current BF, and another old friend are going on a 4 day trip and I currently haven't heard from him in a couple days. 

Do you guys think I should be worried? or am I thinking to much of it? 

I trust him! It's just the way she acted and the fact that I'm scared I've made a stupid decision staying with him and I'm gonna look like an idiot if something does happen.