Cat pregnancy runs 63 to 65 days from mating, and 58 to 71 days is the range that still ends with live kittens. Three dates do most of the work: day 21 for palpation, day 25 to 30 for ultrasound, and day 45 for X-ray. Get those 3 on the calendar and the last 10 days become 3 daily observations instead of guesswork. Everything below is about counting, watching, and knowing when to call — the examinations themselves are done by a vet.
Day 0 has to be 1 date, not a guess
Write the mating date down the day it happens and call it day 0. If the queen was with the stud across 2 days, use the first day, which adds up to 48 hours of margin on the due date. Day 63 falls 9 weeks later and day 65 falls 2 days after that, so the due window is a 3-day band, not a single date. A queen bred on May 1 is due between July 3 and July 5, with the wider 58 to 71 window running from June 28 to July 11. A date on a calendar beats counting backwards from a memory, and it is the number every later decision is built on.
Day 21: the palpation window
Between day 18 and day 25, the uterus carries 2 to 4 cm oval swellings that a vet can feel through the abdominal wall in 30 to 60 seconds. Day 21 is the middle of that window and the easiest date to book. Before day 18 the swellings are too small, and after day 30 fluid volume hides them, so a negative at day 35 means nothing. The queen is fasted for 4 to 6 hours before the visit only if the vet asks, and the visit itself costs 30 to 70 USD. A negative palpation at day 21 is repeated by ultrasound at day 30 rather than by a second pair of hands.
Day 25 to 30: ultrasound confirms life
A fetal heartbeat is visible from about day 22 to 25, and an ultrasound at day 28 answers the 2 questions that matter: is there a pregnancy, and is it alive. Counting kittens on ultrasound is unreliable, with errors of 2 to 3 either way after day 40, so it is not the tool for litter size. The scan takes 10 to 15 minutes, needs no sedation in most queens, and runs 60 to 120 USD. If the queen was palpated negative at day 21, this is the visit that settles it.
Day 45: X-ray counts skulls
Kitten skeletons mineralize between day 42 and day 45, and a radiograph from day 45 onward shows skulls and spines clearly enough to count. Accuracy is about plus or minus 1 kitten, which is the best any method offers before birth, and 2 views rather than 1 catch a kitten hidden behind the spine. One exposure is a small radiation dose and is standard practice at this stage. Book it between day 45 and day 55: earlier than 45 and the bones are faint, later than 55 and a large litter overlaps. Cost runs 70 to 150 USD, and the count changes how the last week is planned — a litter of 6 needs more hands on call than a litter of 2.
The schedule in 1 table
| Day | Check | What it confirms | Window | Typical cost |
|---|---|---|---|---|
| 0 | Date recorded | Due date, day 63 to 65 | Same day | 0 |
| 18 to 25 | Palpation by vet | 2 to 4 cm swellings present | 7 days | 30 to 70 USD |
| 25 to 30 | Ultrasound | Heartbeat, viable pregnancy | 5 days | 60 to 120 USD |
| 45 to 55 | X-ray, 2 views | Litter size, plus or minus 1 | 10 days | 70 to 150 USD |
| 58 to 71 | Daily observation | Onset of labor, or overdue | 13 days | 0 |
Add the queen's weight to the same sheet: 25 to 40 percent gain from the mating weight, checked every 7 days from week 5. A queen who gains 8 percent and stops is a different case from one who gains 30 percent on schedule, and the difference is visible on a chart before it is visible in the cat.
The 3 things to watch every day
First, discharge: a small amount of clear or pinkish mucus in the last 7 days is normal, while green, black, or bloody discharge at any point is a call to the vet within the hour. Second, appetite and temperature: a queen who refuses food for 24 hours in the last week, or whose rectal temperature drops about 1 C below her usual 38 to 39.2 C, is usually within 24 hours of labor. Take the temperature once a day at the same hour from day 55, and stop taking it if it upsets her. Third, behavior: nesting behavior 24 to 48 hours before labor, restlessness, and visible contractions. Contractions that go 30 minutes without a kitten, or more than 2 hours between kittens, are a vet call, and so is any queen who stops pushing and looks dull.
58 days, 65 days, 71 days
Kittens born before day 58 are premature: 60 to 90 g, little hair, and poor suck, and they need a vet's help in the first hour. Day 63 to 65 is the center of the distribution, and about 60 percent of litters land inside it. Past day 69, the queen is checked rather than watched: an X-ray or ultrasound looks at fetal movement and heart rate, because a pregnancy that runs past 71 days with no labor signs is a problem, not a long pregnancy. Roughly 5 percent of queens go past day 69, so a late date alone is not an emergency — a late date plus no movement on a scan is.
Weight, vaccine, and the last 2 weeks
Two records run alongside the due date. The weight log catches a stall 10 to 14 days before it is obvious, and a flat week after day 42 is a reason to scan rather than wait. The vaccine timing question is settled before mating, not during pregnancy, and any vaccine given while a queen is pregnant is chosen by the vet, with killed products preferred and modified-live products avoided. Budget the 3 visits at 160 to 340 USD total, against the cost of a litter that arrives with no due date at all.
The next 7 days
- Day 1: write day 0, the day 63 to 65 band, and the 58 to 71 outer window on the calendar.
- Day 1: book the day 21 palpation and the day 28 ultrasound in the same call.
- Day 3: start the weekly weight row, with the mating weight as the baseline.
- Day 5: put the day 45 to 55 X-ray on the calendar, with the 2-view request in the note.
- Day 7: draw the 3 daily observations — discharge, appetite and temperature, behavior — on 1 sheet.
The 3 dates are cheap compared with a litter that arrives 8 days early with no one ready. If the pregnancy was not planned, spaying the queen after weaning is the default, and the next 63 days never need a calendar at all.
Frequently asked
How long are cats pregnant?
63 to 65 days from the mating date, with 58 to 71 days still producing live kittens. About 60 percent of litters land inside the 63 to 65 day band. Kittens born before day 58 are premature at 60 to 90 g, and a pregnancy past day 71 needs a vet check rather than more waiting.
When can a pregnancy be confirmed?
Palpation by a vet works between day 18 and day 25, with day 21 the easiest date to book, and ultrasound from day 25 to 30 shows a heartbeat. An X-ray at day 45 to 55 counts skulls to within 1 kitten, which is the most accurate litter size available before birth.
What signs mean labor is close?
A rectal temperature about 1 C below the queen's usual 38 to 39.2 C, nesting behavior 24 to 48 hours ahead, refusing food for 24 hours, and visible contractions. Green or black discharge at any point, 30 minutes of contractions without a kitten, or more than 2 hours between kittens are all vet calls.