Having dog spayed after having puppies

We adopted Precious from the SPCA. Before we adopted her she had a litter of puppies. Of course, we want to get her spayed, but when the SPCA called the vet they booked us an appointment for March 28th. How long after having puppies should we wait before getting her spayed? The puppies are now 10 weeks old. I can understand letting her body get back to normal, etc. but I'm afraid that she will go in heat before being spayed.

Yes there is a chance she could be in heat by then, since dogs experience estrus around every 6 - 7 months.

It's not a big deal if she is. Just reschedule the spay for a month down the road.:)

Our last dog was in heat when she was supposed to be done, we just rescheduled then. Of course, I watched her like an hawk. She was always attached to us, so that no males could get near.