Questions for you: Are you diabetic, because if you are, you could have broken it and because of loss of sensitivity to the feet with diabetes, it would go undetected and not hurt. If not diabetic, Is your foot reddened also? Could be a possible infection. Have you checked your pedal pulses, (pulses in your feet) because maybe you are not getting sufficient blood to your foot or have a clot. Either way, I wish you the best and please seek medical attention.
i would really check in with your dr its a possiblility of a fractured bone only because from the sound of it you can walk on it but it hurts so the fracture