Sometimes it seems like a cat is constantly in heat; it can last anywhere from a few days to several weeks, plus it can reoccur every two to three weeks.
Heat cycles in unspayed cats repeat every two to three weeks, usually beginning in January or February and continuing until as late as November. These cycles will last for four to seven days.
cats go into heat often sometimes every two to three months. I had a cat that had kittens in may and then again in august. and when we took her to be fixed in january she was pregnant again.
If a cat isn't pregnant she'll go into heat every few days until she is. 63 days later there'll be kittens. They'll be weaned in 4 to 6 weeks, then she'll go into heat again. Three litters a year is easy for a cat.
