I am driving myself crazy over here!!

Last week around the time my period should have been I had what I think has to be implantation bleeding. It was NOTHING like a normal period. It was light, it only lasted 2 maybe 3 days, it was a lighter color, absolutely no clots, and I didn't feel like I normally feel like I do when I'm on my period. Now today, a week later I took a pregnancy test and it came up negative. Am I reading too much into this? What is happening to me? Has anyone experienced anything like this? Could I still be pregnant?