I have black-ish discharge...?

i just went to the obgyn and i have an ovarian cyst. well i knew that already from before, but he did an internal ultrasound and when i came home all was fine. but its been 2 days and today i wiped [[tmi sorry]] and there was blackish discharge and like alot. i havent had my period but im not pregnant we already ruled that out. now can this black discharge be from my internal exam? like could the lubrication he used for the ultra sound probe have anything to do with it? cuz like i said this didnt happen untill after i came home from this check up or can it be that he knicked my cyst and its erupted? i am going to call them tomorrow but i was just asking to see if anyone else had this problem. also i dont think it matters but i have a 10 month old son and im 18. and there have been no miscarriages . i appreciate all answers thank you!