You are on top of your charting! Because of this, I'm going to assume you're probably trying to conceive (or possibly trying not to). If you had sex on or around your fertile days (so, CD10-CD15, give or take), then there's a good chance that your symptoms are indeed related to pregnancy. I wish I could say that cervical mucus is a reliable way to detect pregnancy but (and I'm not a doctor) I know that all of us women are different and we don't necessarily experience the same types of cervical mucus for each part of our cycle. So my best advice concerning that is just to take note of what is normal for YOU at this point in the cycle. If this CM is different than your normal CM at this time of the month, then that may be a pregnancy sign as well.
As I'm answering this, you should be around cycle day 25, and if you have a usual 28-day cycle, then it would be okay for you to start testing. With each negative test, you should wait two more days to test until you officially miss your period.