TMI Pic - Brown Spotting, could it be IB or BC side effect?

Lindsey

I quit the bill a little over 4 weeks ago and have had all sorts of weird symptoms on and off since (sore nipples and boobs, nauseous, vivid dreams, insomnia - all that come and go). Assuming I have a 28 day cycle, I should've started last Thursday but didn't. Instead I've started spotting light, watery brown on and off since Sunday and have had little cramping but a stretching feeling in my uterus along with LOTS of dizziness and fatigue.

I took a pregnancy test last Friday and it was negative. Could I be having implantation bleeding (since I'm not exactly sure when ovulated) or is this a weird "first" period off the pill? Anyone have a similar experience???