I started microgynon at 14, as soon as my periods started as they said it would help with pain. Because I took it to aid the pain, I had to change every 8-12 months, because my body would get too used to it. I started on microgynon, switched to a few others, went back to the microgynon and got pregnant after roughly 4 months of taking it, just after my 17th birthday.
I stopped the pill last feb, and according to my calendar,this was my cycle;
Feb - March - 37 days
March - April - 27 days
April - May - 29 days
May - June - pregnant, m/c
June - July - 30 days
July - August - 29 days
August - Sept - 3 days(!!)
August - Sept - 27 days
Sept - Oct - on CD 25 as we speak
As you can see, I had one period nearly straight after the other 6 months after I stopped!! I went to docs in a panic, they said this was normal and was just my body flushing out hormones. Also if you are on a progesterone only pill, you can lose a fair bit of weight after you stop, as there is less progesterone in your system being made naturally, so there's a big influx of oestrogen. The oestrogen clings to fat, and then basially you wee out the fatty oestrogen!! Lovely!!
We are going to use BBT as contraception as I don't want to screw with my cycles anymore. Also, when I was on the pilll I had to spend two days of my period on total bedrest, as I couldn't even bend over with the pain, but now, although they are painful, I have actually found they are 100x better. I take paracetamol for 2 days, but they are manageable, I can still work for example.