Am I having implantation bleeding? PLEASE HELP>?

Yea. So i had bout 4 or 5 times w/o a condom & i dont have birth control. We were just bein dumb...but now its getting really serious. I dont know how long these things are supposed to take, but right now (for the past 2 days) ive been having this on and off light spotty bleeding. i just wear a pantyliner. there's never enough for a tampon or a pad. Yeah. And usually my periods are REALLLLY heavy. so idk whats going on. Is this implantation bleeding, or what could it be. Please help!