First of all I hope you have seen a doctor about this.
I did not fall when pregnant, but when I was way far along pregnant with my first, I had really acute pain in my ribs . I found out, it was due to pressure on my ribs, kind of pushing everything upward. My belly was so big, that it was making this painful pressure on the cartilage and ribs just between my breasts and my stomach. If you can picture that.
I wonder if it's coincidental that you may also have this pain, maybe nothing to do with the fall you had.
It was really hard to figure, it took weeks till my doctor and I realized what was causing this pain!! And needless to say the pain was gone after the baby arrived.
Hope you feel better soon. I hope it isn't broken ribs after all.,
Lynie