Spay surgery site looks odd?

My newest dog (from the shelter) was spayed on Wednesday. She wasn't too swollen. And seemed okay to me. On Friday she developed a little redness, I called up the vet and she said that was normal. On Saturday there was more redness, but it looked more of an irritation. Like she had messed with it. With one red splotch at the top of the incision, and another and the bottom.

Today the incision was a bit more swollen. Just to the right of her incision site. There is no weird oozing, and she isn't behaving as she is in pain. She even let me examine the site, etc.

I can't call the vet because they are closed this weekend, this also isn't our normal vet. This is the shelter's.

Can I please have some reassurance? I don't want her to be in severe danger.

Oh, and her stitches are dis solvable if that means anything.