The LBS I go to has a Monday night "show and go" ride that is about 12 miles and supposedly pretty low-key, and I'm thinking about showing up for one to try it out. However, I have never done a group ride before, am a pretty new cyclist (got into it a couple months ago for utility and recreational purposes) and ride a hybrid with 38c tires, not the fastest setup. And I'm not exactly a speed demon myself. I also am not sure how many people go on this ride and whether I'd be the only female (which would make me nervous given that I wouldn't really know any of the guys other than the shop owner). So...what do you think? Does it sound like a good idea to try it, or does it sound like a recipe for a fiasco? I don't want to be that person who slows down the group, or get dropped (since I don't know the roads where they go, getting dropped would be a problem!).

Edit: I know I can do 12 miles; I did about a 16 or 17 mile ride this past Sunday that included a couple of wicked hills, but averaged probably 11 or 12 mph (estimate).