I hit my foot in march&hurt my big toe its been swollen&i can't bend it since then should i see my doctor?or go to urgent care?could it be dislocated?

Yes: Any of those options are good. You need to have it looked at and get an X-ray at the very least. Get well soon!

Water cast.: There could be a whole host of reasons why your big toe doesn't bend, especially after be traumatized. Certainly dislocation is a possibility. Others to consider are fracture, tear or rupture subluxation. To remove all doubt, your best bet is having the evaluated by a specialist directly.