CM question

So today I am 15DPO, I'm supposed to get AF today, nothing yet! 
​However my CM is pretty weird right now. It's mostly watery when I check, but if you really look at it, it's kinda white? But then one time I was checking and there was like a big glob of creamy CM. 
​I took a pregnancy test last night, it was neg, but maybe it was because I took it at night and my period isn't late?
​What do you ladies think?