I know how difficult the decision is. When I was constantly having a show for 3 months I was thinking bloody hell, is it always going to be like this. I asked the doc if I could change to the coil after about 2 months and she said of course I could, but if the coil caused a problem too then I could be back at square one.
She said it was always worth the wait of 3 months to give your body time to settle into things - and she was right. As I said after the 3 months, everything turned around overnight. No bleed, no PMT, lovely skin.
So maybe you should give the pill 3 months and if you're lucky like me then great, but if not then you know you have another option.