Should I worry

My period was supposed to come on Wednesday but it didn't so I took a pregnancy test on Thursday and the result was negative.

Today (Friday) my period came! I'm having A LOT of cramps but the flow is a little lighter than I normally get. It started in the morning and now (night) I already used 2 pads (medium ones).

I'm not crazy, the blood is not from implantation, right? Lol