Constant BBT? Help?!

Me • Sun, Dec 07

I just put in my bbt for today and glow popped up a thing that said my bbt is constant and that women usually experience an increase after ovulation..what does this mean? This is my first month using glow and charting my bbt but I thought I am 4/5 DPO. Positive OT on the 2nd and a temp spike but I've been having slight cramping..help!