Ok, so yesterday and today I have been spotting really lightly. Not enough for a pad a tampon, just when I wipe. I'm on CD 17. Glow shows that my next period won't be until Dec. 20th. I have long cycles. I had light cramps yesterday and just slightly a little stronger of cramps today. Not sure if it matters but I've also had a tension headache the past 3 days. Am I getting my period really early or could I be experiencing implantation? Or just spotting?