Talk to Gynecologist on Cyst Or Growth Behind Ovary

yesterday was my first date of menses and i had severe pain in abdomen at night with pressure in lower abdomen. in morning no unbearable pain but dull ache and pressure at same place. i visited a gynae dr and she said rule out upt first. i took upt two days before and it was negative, and started my period.. is this really a period? flow is medium and is reddish to brown jn color .usg shows a small growth of2cm behind uterus. i am also taking clomid for pregnancy... kindly advise what to do