Wasn't included in first round of invites...should I still go?

[Reverend Q]

A few hours ago, I got a Facebook invite to an event that was created a month ago. It's very clear I was not initially included in the invite list. It is a Murder Mystery type of party, so I am assuming that there may only be a certain amount of guests, so when enough people declined I got invited. My first instinct was to accept the invite and go and have a good time, but now I'm starting to think otherwise.

In this "group" I'm not very well liked by maybe 2 or 3 people for things I did about 3-5 years ago. Mostly for reasons I am not fully aware (only guesses). Either way I am not at all the same person I used to be, but if they don't like me or want to spend time with me, I can accept it. So if some of these people are going to be at the party, should I just not go? I wasn't included initially anyways, and what if it was just a pity invite type of thing. I'm also slightly hurt that I wasn't on the first round of invites...but I think it is rude to just ask my friend why I wasn't invited the first time...Should I ask? Should I go? Any advice?