EWCM or preseed?

Lauren • Married August 2014, boy mom, first 💙 born July, 2016, #2 💙 born December, 2018.
According to Glow, my fertile week started last Sunday. Hubby and I did a  lot of BDing all week long and used preseed each time we did. I keep testing with opks 2-3 times a day and still no positive. I did notice some times of EWCM when wiping, but I don't know if it is natural or from the preseed? Currently on Cd 19 and still no positive opk. Any thoughts??