How to know you re ovulating accurately?

Use an OPK kit. If you have regular periods you should be ovulating - you can use an ovulation predictor kit (opk) - test between 10 am and noon, starting on day 10 of your cycle. The first morning urine is not as accurate. Try the ovuquick brand if a drugstore test doesn't work for you. The day of a positive test and the next 2 days are your most fertile days. If you have irregular cycles see a rei specialist.