Opk helps with predicting when you should ovulate which is 24 to 36 after a peak but how do you know you are ovulating? what do you feel? i know about cramps and egg white cervical mucus but how do you know for sure you're ovulating?

Ovulation tests: Calculate the day Cycle length-17 Ovulation testing should be done for next five days. Dynamic Ultrasonography can confirm follicle growth of 1.5 to 2 mm/day. 20-22mm size correlates with ovulation. Serum progesterone level a week before expected periods above 16–20nm/L indicates ovulation. Basal body temperature shows drop on the day or ovulation before rising at least 0.4 degree C. Hope it helps