What Causes An Early Period With Pain In Ovary Region?

ive had sex with my partner 5 months ago. We didnt use any contraceptive method. however i have took the morning after pill within less than 12 hours. after few days i had my periods and they were normal. however after that i had an week earlier period and after that one i had a two week earlier one. now im having pain in my right ovarie. can this mean im preagnant ?