Help! New to TTC

According to Glow, I am two DPO. I’ve been using opk’s to track when I ovulate, however, they’ve all been negative. I’ve noticed my cm is white and creamy when not aroused, but when I get aroused my cm is more like egg whites. Can my cm switching like that still signify that I’m about to ovulate? Also, how many days “off” has glow been for you guys in determining when you actually are ovulating?

Thanks! The topic of TTC is all new to me! Any help is appreciated.