Am I experiencing implantation bleeding???

Ok so I'm on the pill and have been for over a year now. I sometimes skip my placebo weeks so I don't bleed and just go right to the next pack. I did that with the most recent, and I am on week 2 of my pill pack. For the last 3 days I have had VERY light brown spotting that doesn't even need a panty liner, I just see it when I wipe after using the bathroom. I've had some mild cramping-nothing serious- a few other symptoms that have me feeling weird. I've been WAAAYY overly tired, had insomnia for the past week, been eating everything, and having hot flashes/night sweats. I'm 21 so no way it's menopause LOL. Any advice or input? I took a test and it was negative but I know if it is implantation bleeding then I have to wait a few days before I get a positive test.