A female cat may experience decreased fertility over time, but there is no limit on the amount of litters a cat can have. A typical female cat is able to go into heat and become pregnant when she reaches sexual maturity, which is typically at 5 to 9 months old.
Heat in a cat normally lasts about seven days, but can be as long as 21 days in some cats. A cat that doesn't become pregnant repeatedly goes into heat until she becomes pregnant. The gestation period is typically around 67 days for pregnancy, and a cat can have up to five litters in a year.