Negative OPK but EWCM

I've been TTC for three months now (my second). I'm concerned that I'm either not ovulating, or ovulating at inconsistent times. Last month I used the opk when I was "supposed" to be fertile and never got a positive result. This month same thing, however I still have a few "fertile" days left. Today I noticed a stretchy-eggwhite consistency CM. Ovulation apporaching?