CD21. Missed LH surge?

Question. Today is cycle day 21 for me. I have been using digital ovulation tests since day 10 with FMU (bc that's what the box said to do) and have all been negative. Started testing twice a day CD18. Last month I had a +OPK CD20. With a 32 day cycle. The month before was 33 day cycle. I am wondering if Inmissed my LH surge and ovulated around the 15th this month. On CD14,15 I had a heavy amt of watery CM (sorry TMI) I was sick last month and wonder if that's why I ovulated late. Anyone else? Or any advice?