Girlfriend doesn't want me to go with her to parties?

I discussed with my girlfriend how it bothers me that she doesn't want me to go to parties with her. We have only been dating for 2 months but she says she loves me and everything and she knows that I am worried about her cheating because she is drunk at a party. She says she would never cheat on me sober or drunk and I believe her about the sober part. But I know how people can get when they are drunk myself included and this is why I tend to limit my drinking to one or two beers so I don't do anything I regret. She claims that the reason she doesn't bring me with is because she knows I would be watching her and my response was why would it matter unless I see something I really wouldn't like. I'm not the kind of guy that really gets upset about my girlfriend doing a little flirting because thats just the way she is, but she knows this so I still can't see the problem. I am away at college (only 40 miles away so we do see each other at least once a week) and she never has even questioned me about going to a party by myself but I have never said I don't want her coming with either. She always tells me that she will never cheat on me. The reason this is such a big issue is that I was cheated on in my past relationship so it is always a concern of mine. I believe that she wouldn't but alcohol changes that. The other problem is that I think that I come across as a control freak or that I don't want her to have fun which is as far from the truth as you can get. If she looks at this as a kind of girls night out then fine but there are guys at these parties so I'm a little wary. I don't want to hear from everyone that I should just leave her right now b/c that wont happen. She has done nothing to break my trust. I just want some opinions on whether I'm being too worried or is she maybe doing something she thinks I wouldn't like (not cheating) or a little of both.