implantation bleeding

Alena
I was suppose to get my period on the 6th of may didn't get it until the 8th had it for a day but it was brown spotting, then it's stopped then it came back again as just brown spotting and now today I started bleeding red blood, I don't know what to think about this anyone have had the same issue, i took 2 test from Walmart and both came back negative. Help!!!!!