The reasons why cats don’t show a big belly after 46 days of pregnancy:

1. Misremembering the date of mating. If a male cat and a female cat live together, and the two cats mate more than once during mating, it is possible that the actual pregnancy date is not the day the owner saw it. So the kitten is not fully developed yet.

2. There are not many kittens in pregnancy. If there are only one or two kittens in the mother cat's belly, and the mother cat has a thicker fat layer, the pregnant belly will not be obvious.

3. The pregnant kitten is malnourished. If the female cat is in poor physical condition and does not like to eat much after pregnancy, the development of the kittens will also be affected.

4. It is possible that you have had a miscarriage. If a female cat is sick or frightened during pregnancy, she is likely to miscarry. The kitten may be absorbed by the mother cat itself, or it may flow out of the vagina and be eaten by the mother cat.

5. It is possible that the cat is falsely pregnant. Cats will have the same symptoms as pregnancy in the early stages of pseudopregnancy, and may even lactate, but generally all symptoms will disappear in about one month to one and a half months.