I have a strong pain on my right ovary. period is due in 4 days. pain goes through my butt cheek and then travels down my leg, what could it be?

Right pelvic pain: This pain may reflect an ovarian cyst, which may have ruptured (common) and should resolve quickly (1-3 days). If it doesn't resolve, you will need a pelvic ultrasound to confirm if there is a cyst and what kind of cyst. The pain could also reflect ovulation, but that is usually anywhere from day 12-16 of menses (avg is day 14) but shouldn't radiate down you leg and pain is that day only.