Help...informal wedding invite

[Lil' Hannah]

OK, so I started my job in early May. A woman I work with had just gotten engaged and they had planned a wedding for September. I of course wasn't invited because the woman didn't know me well.

The wedding is this weekend and today we were talking and she invited me to come to the wedding. She said something like "I know it's just an informal invitation, but you can come." I don't know if I should go or not. I love weddings and I like the woman I work with, but I don't think she'll be too broken up if I don't go. Other people from work will be there, and I think it will be fun, but I'm wondering if she was just inviting me to be nice.

ETA: I work in a very small office and by "other people from work will be there" I mean the entire office will be there. Also this woman and I have become friends and it wasn't like I was standing there while others were talking about the wedding. In fact we were talking about something totally different, and it was just she and I.