implantation bleeding??

usually I get my period every month on time and this time I was just spotting dark brown light pinkish I didn't know if it was implantation bleeding so it happened a couple days very light. so I took a pregnancy test came back negative. so I fugured my period is probably coming soon and this whole week its just been spotting very light i usually get it a little heavy with clots and all but no clots its been a week and idk what's going on? maybe I should test again? anyone else have this?