If you'd broken it you wouldn't be able to put any weight on it but you may well have a stress fracture of perhaps your 5th metatarsal bone. Based on personal experience - it's excruciatingly painful.
See your doctor for an answer asap is my advice. Better to be safe than sorry.
I'm with Fluffy on this one. It is possible to have a broken foot and not know about it. I thought I had a bad sprain an weak ankles. Five months later I found out that I had chipped a bone in my ankle.
Would be best to have it check out. Better to be safe than sorry.