Could I, couldn't I?

Chelyn

Hi all. i am 7 days late today and yesterday i thought i was starting my period so put a tampon in and all i got was a little bit of dark brown/pink on the tampon. Today im back to there being nothing in site and woke up with a little bit of vertigo. Do you think it could be implantation bleeding? i took a test the other day and got a vvvvfl but after all the other tests said negative. Just a little confused