Implantation Bleeding? HELPP

December 3rd I started spotting like a light pink ( very light bleeding Not enough to even go through my pants just spots) December 4th comes along and throughout the day I would notice spotting here and there not much Yesterday the bleeding became a little heavier not much and Ive started having slight cramps Today I'm still spotting and I'm so confused. My period is due The 13th I don't bleed lightly, I usually bleed very heavy during my period. I've been vomiting for over a week on and off and I took a pregnancy test a few days ago and it was negative I'm so confused😐😐