Trying to fall pregnant

I've been on the pill for roughly 2months now after the implanon was making my periods go all over the place and my sex life wasn't doing too well.I changed to the pill to get my periods once a month for the 7days plus I've also been trying to get pregnant whilst being on the pill.I'm finding it harder then usual and if I don't take the pill for a day or two I start to have cramps and bleed. Any ideas?!