Fertile window - physical symptoms

Diana
I'm in my fertile window. On Monday I felt some cramping, but it did not last longer than 15 minutes. Tuesday night they came back and I have felt cramping/pressure pretty much all day today. I'm also having some nausea. Today is my peak fertility day according to Glow. I haven't seen any cm yet today but I did have some Sunday - Tuesday. It feels almost the same as when my period is going to start. This is my second month without my IUD so this is new to me, any explanation of what is my body is doing right now? Does the constant cramping feeling mean I'm ovulating today?