Same thing happened to me, but I had the implantation bleeding 3 days before my period was due. When I took a HPT test before the implanatation bleeding it was negative, then I took the test 2 days after the implantation bleeding and it was positive, so it can very be that you are pregnant. Good luck and let us know.
Hey! Im kind of in your situation. My cyce suppose to start on the 11th which is like 4 days away, but starting yesterday I been having a pink discharge