does a hairline fracture always hurt to walk?

well its definitely a possibility that i have a hairline fracture in my foot because it was slammed in a car door yesterday. it was very swollen yesterday and it hurt to bend my toes up or down. I also was a bit nauseous after the incident. It was also cold and numb. (why would it be cold and numb?) Today the swelling has increased dramatically and i can walk just fine. However, the bruising has increased a great deal and the pain is more localized. my foot was a bit cold again this moring (the other one has been normal this whole time) and it was tingling earlier. The thing is that yesterday i was fairly certain it was fractured and now im not so sure. Has this happened to anyone else and if i didn't go to the doctor and it turned out to be fractured, would it get better on it's own or would it eventually get worse? any answers would be appreciated. :)