Could I be pregnant?

Right here’s the dealio. I was on the depo injection for 6 months and i’ve been off it since about august. I bled for about 5 weeks none stop and then i didn’t have a period at all for 8 weeks and thought i was pregnant. Turns out i wasn’t because then i got my period and i’ve been on and off ever since. My boyfriend and i have been having unprotected sex since i thought i couldn’t get pregnant for about a year anyway and he always pulls out. The thing is for the past week i’ve been feeling sick and dizzy, today i just can’t stop weeing even though i haven’t drunk that much. I took a test this morning as soon as i got up and over about 6 minutes a very faint line was developing. Could this be a positive? I have no way of knowing when i’m ovulating because my periods have been all over the place so i don’t know how far along i could be. If i am though i’m so confused because i’m on the pill now to settle my periods down but i’m still bleeding so doesn’t that mean i’m not?

If this rant made any sense to anyone then i’d be really grateful if you could give me some advice and maybe try and clear some of this up for me.

Thanks a bunch,

Yasmin
Aged 17