Advice :)

I'm on the pill but I'm very bad at taking it I miss lots of them any way me and my boyfriend have sex quite often without any protection (never gotten pregnant before) I'm 17 and he's 18, but my last two periods haven't been the same they've been on time roughly but I'm usually a super heavy bleeder and usually have clots to the point where I have to use maternity stuff, but my last two have been nothing, recently I've noticed I've been getting a lot of headaches which aren't common for me, I am getting dizzy which also isn't common I've been nausea and very very tired, I get stomach cramps every so often but not super bad ones (I never get cramps) I've also noticed some sort of like constipation but I tend to eat stuff with fibre and drink water, I'm usually a person that hardly needs to go wee but I've been peeing a lot more then usual lately, I've also been getting lower back pains and darkening areole also my breast feel heavier,  I'm not sure if I'd be pregnant or not so I haven't tested or anything but if I was I'm not sure how far along I'd be seeing as I've had little bleeds here and there but hardly any to the point where I could use liners me and my boyfriend would be excited to have a child but we aren't planning it, any advice?