Normally no. However there seems to be some recent cases (including my own cat, Ling) where the cat was spayed and months later came "into heat" with all the signs. So far, the problem seems to be cysts growing in the area where the overies were and causing the symptoms.
Ling had to undergo another "spay" and that was what happened.
it depends on how long ago your cat was spayed. if recently then it could be the hormons still in her system which will calm down soon. but it dosnt hurt to have her checked over by a vet in case of cysts like goldenkitty said