I think that I tore something

It has been 3 months since my surgery and I was walking around a store and something in my foot went pop. And it hurt. I could still walk back to the car, but I was limping. When I got home and took off my shoes, standing on one foot to take off the other sock was excruciating. And the back of my leg by the stitches looks different, relaxed.
Right before this, I almost slipped on a greasy floor at a restaurant, but I caught myself. I called the Doctor, and I go in 1st thing in the morning. I hope it isn’t ruptured!!!