I'm sitting her twisting and cringing at the thought!!!! I fell once, in the hospital with DD2 at 36 weeks, they hooked me up and caused such a fuss, I kept saying I was fine, gave my MIL a nasty scare. They wouldn't let me go for hours. Glad they checked me out though. When she was born I had a cup of blood clotted above my placenta, it was a slow bleed, It was an abruption, none the less. She also weighed less then DD1, which makes me wonder if she was starving in there for the last few weeks, my poor baby. They think it was from the fall, I had been having a bit of a cramping pain up top, but it was pretty dull so I ignored it. There was all sorts of drama when I gave birth to her, but that's a whole other story.
With DS I was about 28 weeks when I gave my MIL a second heart attack by falling front first down her steps but landed on my forearms , bruised and battered I was fine and so was bubs.

I would get checked out just to put your mind at ease.