Bleeding after orgasim

So this is an embarrassing question, but the other day I had an orgasim (w/o penetration) and then about a 1 1/2 days later I had a bright red bleed for about 15 - 20 minutes. It has now stopped. .but I still called my Dr and they ordered me an ultrasound to be safe. Although, they didn't seem too concerned. .i think they ordered it more to ease my anxiety. I wanted to see if anyone else had something similar happen?
I have had NO cramping 
I should also tell you that I have SCH. I've have it since about 5 weeks and had some bright red bleeding in the beginning that turned into spotting. I'm now 13 weeks. I realize there could be a handful of things that could have caused me to bleed again, I just wanted to get other people's opinions. Thank you in advance!