I'm a complete wreck! Please someone tell me about their implantation bleeding? Does this sound like I could be experiencing it?

Had sex during fertile week twice, the day my period should have started i had brown then red streaked discharge. Day two and three was light light bleeding, and the last three days including today was brown, pink, and some reddish spotting only after I go to the bathroom and it has ALWAYS stopped during the night? Anyone experience something like this? I'm hoping this means im pregnant because my periods are seriously heavy, but I've yet to get a positive result? I also breastfeed, maybe too early to test?