When can a Dog Become Pregnant?

Dogs are sexually mature between 6 months and 1 year and a females first cycle can be anywhere from 6 to 18 months of age and she will go into heat twice a year. The heat cycle of the female lasts from 18 to 21 days. Pregnancy in dogs lasts two months, or sixty days and a litter of puppies can be as many as 12 or as little as 2 or 3 depending on the type of breed you have.