Period or just discharge??

As

Hi all so i had a MMC 4 weeks ago last week i went to get the ultrasound and i was cleared and the dr said it looked like i was gonna ovulate so i think I ovulated some days after i got the ultrasound because i had a lot of pain, im still in pain but now is different like if im getting my period but i just got like light brown discharge like if my period is starting but it comes and goes just started todayanyone had this happened??? Also my dr said to come day 3 of my period for an ultrasound but I don’t know if i need to consider today as the first day!!!