Depends on the species.
mice and rats are pregnant about 3 weeks while elephants average 92 weeks - nearly two years.
A horse's pregnancy typically lasts around 11 months, or roughly 340 days on average.
The average Dog pregnancy lasts for around 9 weeks from time of conception.
The average pregnancy for any breed of dog lasts for 9 weeks.
About 280 days. Typical pregnancy is 40 weeks. 40 weeks x 7 days a week would be 280 days.
Hedgehogs are pregnant for 32- 42 days. Average pregnancy lasts about 35 days. 1-10 babies maybe born to Algerian and African Pygmy Hedgehog breeds.
A pregnancy usually lasts for 9 months
a full term pregnancy lasts 40 weeks
A pregnancy lasts for approximately 40weeks
Approximately 10% of pregnancies end in preterm delivery, defined as a delivery that occurs before week 37 of pregnancy (the average pregnancy lasts 40 weeks).
Around the end of January 1988, it is impossible to be precise but the average pregnancy lasts 9 months.
The average dog pregnancy lasts 63 days. It can be a few days longer or shorter.
11 and a half months (a year being 52 weeks) the average pregnancy lasts 40 weeks (9 months)