Bleeding after ultrasound

Went in for my 20 week ultrasound yesterday- it's a boy! Had trouble getting good pics, because nugget was being difficult 😜 I had an episode during the ultrasound; and had to lay on my sides instead of my back, to keep from passing out. Everything seemed okay, ended up puking on the way home- but I've had awful nausea the whole pregnancy so that didn't seem odd. But when I got home I started spotting. I ended up getting something to eat, because it's the one thing that makes me feel better haha. Then, though, I started to have period like cramps and period like bleeding- think dark red, and enough to fill the toilet (TMI I know, sorry). After a trip to the ER, bleeding thankfully stopped but cramping is still there. Gonna have a follow up with my Dr. to try to find the cause. I was wondering if anyone else has had this happen?