cat birth

Question
How can you tell if a cat has given birth.  My cat may have had kittens outside.  
Her belly doesn't seem as full.  She is on day 61.

Answer
Hi Jenny
A normal gestation period for cats is about 60-65 days.  Here is a link to an article that explains the sign and symptoms that will help to answer your question.  It is just too long for me to copy into this answer;
http://www.cpvh.com/Articles/37.html
With thanks,
Silva.