Birth Control?

Need some help from those of you who have already been down the WLS route...  I am probably having my surgery in March but have been having a discussion with my primary doc re: what kind of birth control to use post op...  My periods have been getting closer and closer together (every one to two months) so I definitely need to have something figured out.  I am not sure that I ever want to get pregnant (we have two kids) but I'm not sure I want to make that permanent yet... so, any info or suggestions?  Being over 35 I'm not too excited about the regular pill but my doctor has mentioned a "mini-pill" but I don't really know anything about it...    

I got the IUD for 5 yrs. I love it. And then its not permanent but your good for 5 yrs.