Advice?

Hi! So Glow said my period was due last Saturday (the 7th) when my period last month was December 11th. Anyways, I was late, I took a pregnancy test and it said negative. And today (the 10th) I just started having light pink VERY light blood. I also have sore boobs, which never happens to me, cramping, headaches, super tired, and a little nauseous. My question is, is it possible to have a negative test, then have implantation bleeding, then get a positive like next week or so? Basically, could I still be pregnant? Thanks!