Hi Alexis and welcome. Certain dietary changes can cause red or orange urine. If it is blood it will usually separate from the urine in blotches. Blood is not normal in urine and take her to the vet ASAP if that is what it is. Have you ever noticed her pee red or orange before?
You want to make sure she doesn’t irritate the incision as it might become infected, or worse, she could break open the incision. If you find she won’t leave it alone, I would call the vet and they may recommend placing a cone on her so it can heal. Since she seems to be acting O.K. and there were no traces of blood, she is eating and pooing O.K. I would keep a close eye on her to see if it happens again. If so, give the vet a call. Did the vet prescribe any pain meds?
Here is a recent discussion on a spay one of our members went through:
https://binkybunny.com/Default.aspx?tabid=54&forumid=2&tpage=1&view=topic&postid=17164#21713
This is also from our FAQ & Helpful info section:
Spay/Neuter Questions – Finding the right vet, pre & post op expectations
https://binkybunny.com/Default.aspx?tabid=54&view=topic&postid=13556&forumid=6&tpage=2#13954
First-hand advice & assurance: https://binkybunny.com/Default.aspx?tabid=54&forumid=2&tpage=1&view=topic&postid=17164#20010