help me out ladies

Klarissa

In so very confused. I usually have a normal 27-28 day cycle. I ovulated late this month at cd 18. Does that mean my period and cycle are going to be pushed back. Glow says my period isn't due for another five days, fertility friends says my period will be in about 3 days. Which one is it? I'm currently cramping like my period is going to come soon although I wish it wouldn't.