Implantation bleeding?

Okay well my periods are normally heavy or medium flow, this month I was few days late had no cramps still none but I've been spotting on and off just enough to wear a panty liner, and been spotting for bout six days now but it comes and goes! I'm wondering if this is implantation bleeding or just a light period!!! I took a test the second day I missed(late) and it was negative I'm trying to conceive but I don't wanna take a test and see negative results like always ?! Oh and my blood was brownish/pinkish