Clarification please!

Emily • Pregnant with #3! Due May 6th 2015
So I've been trying to figure out why Glow set my next AF date so far back. 
​I had AF 2/1. I have a regular 28day cycle which would put my next AF at 3/1 but Glow has it as 3/5. 
​I seem to have ov'd 2/18. 
​So I'm wondering if Glow pushed my period back bc a normal Leutal phase is 14 days? 
​I started cramping yesterday 9dpo and still today with some pink CM today. 
​Now I'm really wondering if this is my period. Or if this is implantation...?