birth control
"Pros: 
didn't get pregnant

Cons: 
had to go on the combined pill anyway to stop a constant heavy and extremely painful period.
Period between packs of the pill was even heavier and more painful. Took over a week of taking the pill again to make it stop. 
Awful mood swings. 
Pain at the insertion site
Once it's in, the NHS will be VERY reluctant to remove it if you have problems
Botched insertion made removal even more difficult difficult when I had to be hospitalised due to the blood loss
Bottom line: don't do it"