Should I be concerned yet?

I recently got off birth control (Depo) which I’ve been on before and usually when I don’t get my shot my periods starts immediately and are regular. I was scheduled to get my shot September 27th. Last time I had sex was September 12th. I have had every sign that my period is coming (cramps, spotting (brown and pink .. lasted 5 days), fatigue, mood swings, sore breast, back pain, nausea) but no period and this has been going on for 2.5 weeks now. I have taken a pregnancy test just for giggles but they looked like bad test (look like dye run or vvfl) but I did get a solid negative once. Should I be concerned? Is it time to call the OB?