Fell down the stairs at 17 weeks

I had a minor fall on Saturday down a few stairs. I landed on my right side, no impact to my belly. I haven't had any cramps or bleeding. Yesterday and today I've noticed some arm/rib soreness, nothing severe but still a bit painful. I called my OB's office and they said it's probably a pretty low-risk fall, but I'm still going in tomorrow morning anyway (it was the soonest they could get me in) so they can check baby's heartbeat and make sure he's okay. I know he's probably fine in there, but I still can't stop worrying about my little guy :(