* Pig gestation period: A sow's (female pig) gestation period is approximately 114 days (about 3 months, 3 weeks, and 3 days).
* Weeks pregnant: You've stated the sow is 3 weeks pregnant.
* Days remaining: Subtract the number of weeks pregnant (3) from the total gestation period in weeks (16) to find the remaining weeks: 16 - 3 = 13 weeks.
* Days in remaining weeks: Multiply the remaining weeks (13) by 7 days per week: 13 * 7 = 91 days.
Therefore, there are approximately 91 days until the pigs' birth.