I personally think the pill is an evil creation. The same thing happened to me when I started taking it in my early 20's. From a size 8-10 my weight fluctuated over the years and I now struggle to keep it off.
I never had any Gynae problems either before going on the pill, my periods from he age of 11 were as regular as clockwork. Soon after starting the pill, my periods became irregular and I was diagnosed with PCOS as well as Fibroids. I also got severe bouts of depression.
I stopped taking the pill at around 30 and would never use it again. No doctor would ever admit my problems stemmed from taking the pill, but I definitely believe they did.