Yes. I can find documentation that oral contraceptives can cause weight gain if you'd like me to look for it. I was on the pill for over 10 years. I was finding it more and more difficult to lose weight and it was making me a crabby pain in the butt and I had never had a baby. So, I went off the pill, lost over 15 lbs and then got pregnant using the FNP method. So much for weight loss!!!
Moral of the story: Don't go off the pill unless you have a reliable method of birth control for back up or you want to get pregnant again. Or don't have sex. :)
I think the mini-pill isn't as high a dosage. Talk to your GYN abou that. Personally, I chose an IUD and love it.
Good luck and keep working at losing the weight with exercise and good nutrition. That's the best way I lost the baby weight and keep it off!