CM Question

So I use two apps, Glow and Ovia. They say different days for my ovulation. Ovia says today is my most fertile day when Glow said the 7th was my most fertile day. I am having trouble tracking my ovulation. Yesterday I had egg white CM and today it's just watery. Can someone please clear up the CM confusion I'm having? Do you ovulation when the egg white CM comes or is that just an indicator your about to ovulate? I've read different things. We've BDed almost every day this week. Also, I woke up this morning having left pelvic pain which I also read is an indicator for ovulation