ATailOf2Kitties, no they do not routinely tattoo spayed females here, but like Jen said, "That is a fabulous idea." I think I will mention this to my vet.

Laura, that is my main concern. Having her go under and cut opened, to find she has already been spayed. I would feel absolutely horrible.

I cancelled her appointment for tomorrow and re-scheduled another one which will be on March 24th. If she doesn't go into a heat by that date, I'm guessing that she has already been spayed because it would be 7 weeks that I've had her and from what I've read, she should have had a heat cycle by then.