
One of my girls did this after her first season at the start of the summer, she was hiding toys, producing milk etc. we tired to get back to normal, taking her for extra walks etc, just to take her mind off things. She ended up with hard lumpy boobs for a while too.
I don't think it will be a pyo, but if you are worried, if she has a nasty discharge or seems generally unwell then take her to the vet.
I'm sure she'll be ok though