Maybe a line ? Not sure if i missed my ovulation

charlotte • TTC 5years due with my first rainbow 9/9/2020

Has anyone ever has really negative opks then all of a sudden really positive ? I was on clomid 50mg first cycle and still getting negative results headaches from hell feeling sick acne bad lower back pain first clomid was January the 10 to the 16th ? I'm not sure if maybe I ovulated really early like a few days after clomid when I wasn't charting