Not sure when I ovulated?????

I’m on my 2nd Round of Clomid 100mg taken cycle days 3-7, LMP 7/4/19. Started off taking digital opk’s on cycle day 13-18 all negatives; then switched to strips on cycle day 19 got varying results all the way up until a what seemed to be positive on yesterday morning which would be Cycle Day 21. I also went to get Progesterone levels checked yesterday and they came back stating ovulation occurred; fast forward to today got an ultrasound and it also verified I ovulated. I’m just so confused on when I ovulated???? To add had EWCM from CD 18, with high, soft, open CP. Any thoughts, or insight please help????? I don’t know when the TWW began....