ovarian cyst or pregnancy?

i’ve been experiencing some weird things the last few weeks. i had unprotected sex and took my birth control pill a few hours late on the 15th of december, on the 25th i noticed dark brown discharge that lasted for two weeks, and then had a short painful heavy period that only lasted 4 days which is not normal for me. i always have long ass periods. anyway, after my period ended the brown discharge started AGAIN for another few weeks until i took a probiotic and suddenly it vanished lol. ever since the end of my period (which i think is what it was) my lower abdomen has been feeling like tight (?not sure how to explain it) and sometimes painful. it switches between my left and right side of my abdomen. also, during my ovulation/fertile week this month (jan) i had a sharp pain in my right side/lower abdomen. it migrated into my hip and right leg as well. however during my fertile week i also had egg white discharge like i usually do during that time, this eventually turned into milky white discharge and now i’m not having any. my period is supposed to start in two days. could this be an ovarian cyst? ive never had one before nor have i ever been pregnant.