Pants too big

So I bought some cute pants at Christmas time for a Christmas Eve party, I am wearing them today and I so have to take a picture, they are too big! The waist is just huge, I so wish I would have taken my measurements before I started, because I can so feel the difference in my clothes! And I'm a little proud of myself, if thats allowed, its a good feeling! I was thinking today I might do weight watchers as well. I've been doing really well on my own, I haven't deprived myself of anything that I want, just small quantity and only a few days a week. I worked out this morning by myself, I've decided to join the spin class on Wednesday, I'm super nervous, and why is that? I've been working out straight for several weeks, I think I can take it up a notch. I think its the fear of the unknown! I'm ridiculous! Wish me luck!