WHAT IS THIS MID CYCLE BLEEDING??

went to the emergency two days ago for allergy reaction

got some medication thru IV one of which kinda burned and hurt down there for a couple seconds

went home there was some spotting

didn’t think much of it

wiped the next day some spotting too thought it’s bc of ovulation being near

put on a pad yesterday at night

woke up w the pad full of dark red period like blood

my period isn’t till two weeks and a half

what could this be

what should i do

my ob is closed today

i’m supposed to go to my fertility doctor on saturday tmro for vaginal ultrasound and most likely insemination

what do i do