Hello Dear Niamh,
Its good that you have taken pills to 5years, its benefits are much more. But if you feel you are gaining weight, get a gynae follow up. And I suggest you should have your gynae consultation every year, get your blood sugar, BP, Liver
function and renal function evaluated. If everything is fine you can continue pills or choose some alternative therapy.
Do reply if you have any further queries. I will be very happy to help you.