Am i pregnant Am I Spotting Whats going on?

Well to start off 4 days ago my breasts started to hurt they felt heavy and like something was pulling on them, also around the same time I was feeling a slight cramp, I was 3 days late for my cycle, but now that I've started I'm not so sure its a cycle more like spotting, my usual cycle color is more a dark brownish like red however this bleeding is more of a bright red, I can clearly notice the difference, the cramps and breast changes still haven't gone and I've gotten a few more back pains, plus the blood isn't how my usual cycle is as far as how much is coming out, its fairly light like two or 3 spots when I check it,! Should I buy a prego test or wait til this is done, and if this is spotting then how long will it take? Will it last like a regular cycle,? And is they're anyone who can help walk me through this?