This is Lucy. You can easily see that she is a calico cat, so you know that she must be female (since it’s genetically sex-linked: all calico cats are girls). What you can’t see is that she’s only about one year old (she showed up at the owner’s home as a kitten one year ago). If you looked at her teeth, you might be able to guess that, though. You also can’t see that she’s an "outside cat" from this picture, but the folks are happy to tell you that (from the number of fleas she’s carrying you might have suspected it ).
Now that you know she is one year old, lives outside, and is a pretty girl, can you guess whether she is pregnant or not? Her owner acted shocked when I told her the joyful news. "How could that happen?!" Actually, a more appropriate question would be how could it NOT have happened?
Cats are seasonally poly-estrous. They are not like dogs. A female dog has reproductive cycles (estrous cycles, "heat" cycles) that last around 3 to 4 weeks, and most of them cycle twice per year, at no particular time. Cats shut down the kitten-maker in the late fall and winter, when the food supply is less certain for them (in nature, anyway). With spring, they begin to cycle constantly. They are "in heat" (sexually receptive and fertile) for four days, out for eight, in for four, out for eight, in for four, etcetera. This continues until the cat gets pregnant, or next winter, whichever comes first.
A cat in heat tends to act a little crazy, yowling and assuming odd postures and behaviors. I have made more than one night call for a "dying cat" who proved to simply be in a lusty mood.
Cats are induced ovulators, which means that the ovaries don’t release the eggs until mating takes place. This means that when cats are trying to make babies, they don’t "miss the day" of ovulation. When it comes to getting pregnant, they are reliable little machines.
After nine weeks of gestation, here come the kittens, and aren’t they cute? Now she nurses them. You’d think she’d be too busy doing this to get pregnant again, but you’d be wrong. It’s quite common for the queen (the momma) to be two weeks pregnant by the time the first litter are weaned.
Cats in Lucy’s situation usually crank out two litters per season, and three is not uncommon. That’s why it would have been kindly old Doc Mobley who was shocked had the cat NOT been pregnant. If you don’t want new kittens around the homestead, you had better hurry up and schedule some surgery for those nubile young cats.