I think my boyfriend is cheating on me?

[kate]

I've been having many struggles lately when it comes to my boyfriend. Let me start it off by saying we are a long distance couple. Our normal talking/skpying routines have changed. They went from everyday for five months to once-twice a week three times if I'm REALLY lucky. This has been going on since January. His family is in the process of moving at the moment and he says he's always busy helping "renovate" his new house & I believed at first it but there have been a few occurences which lead me to think otherwise. For one, he went to his ex's party this weekend and didn't tell me he was going. When I asked if he had plans he said yes but failed to acknowledge the fact he was going to her party. When I asked him if she would be there he said "I don't know" which is misleading to me because she organized the event and invited him on facebook. Thats how I know about it in the first place. After the party he messaged me asking if I was there (5AM) his time (11PM) my time but I was fast asleep so I didn't respon until the morning. He hasn't been on skype since but has clearly been online on the computer. He changed his profile picture, cover photo, and added some really pretty girl who was at the party. NOTE he is not the type to add/accept randoms on facebook unless he knows them really good so I'm kind of worried about it. My birthday is in two days and we are seeing each other in less than two weeks so I really don't want to confront him about all of this and screw things up before the best parts. No, I don't have proof and this is why I'm debating on talking to him about it. But it is really truly bothering me. Should I wait it out and talk to him about it when I see him or now? I feel terrible and it's all really bothering me. Thanks in advance to anyone who helps.