Open Enrollment time.. possibly?

I'm pretty confused with the open enrollment period at my new job. I've been here now over 2 months and so I did all of my benefits when I came in. Usually open enrollment seems to be in November, but not here. I only just received the forms today, and I'm not fully sure if everything is there.

The main new thing is that they're changing health insurance. It's a small company so we only have one choice. I signed up for that choice when I entered and now they're changing to the provider I had before. It's about the same price so nothing really changes much. It just gets confusing because I was told a few weeks ago that I could put my fiance on all of the forms since we'll be married when the new plan goes into affect (Jan. 1st). But now they want to get a special deal so the new plan goes into affect December 25th. But I won't be married yet, so I can't have my fiance on that insurance for that week, which isn't a big deal because she has her own insurance until January 1st. But I then don't want to have to fill out all new forms days after the new plan goes into affected to change it. Seems like a nuisance.

So I'm still figuring it all out. I'm also thinking about the FSA.. but I don't know if that's the best choice because we're probably going to switch plans once the wife gets a new job in september. I just want this to be as little of a hassle as possible, but I don't think that will happen.