Cramping!?

The hubby and I are trying for second baby. My daughter is two. Have been off birth control and TTC for a year now. This is my first month of using glow! Our first child was a suprise, we weren't preventing but weren't planning either.  I've been checking cervix and logging everything. Today is my fertile window per glow. We have BD every day since last day of my period including today. I have been cramping last two days like AF is coming but she's not due until 2/14.  Today I noticed light pink when I wiped?? This is very strange for me I am very regular every 28 days on the dot and no spotting in between.  I had implantation bleeding with my daughter but didn't know it was until afterwards, this seems to early to be implantation bleeding to me.  Any advice?