Pog calculator: Wondering when your baby is due

Wondering when your baby is due? Find out with our easy-to-use due date calculator , plus see your whole pregnancy timeline and what to expect this week. Gestational Calculator Enter either date of last menstrual period or ultrasound information. If both data sets are entered, the calculator will only use ultrasound data. ... Calculation is based on an average 280 day gestation from the first day of the last menstrual period in a woman with a 28 day cycle. Calculate pregnancy dates from last period, gestational age, or date of conception. This calculator is based on the work of Dr. Frank A. Chervenak, a leading expert on fetal biometry and obstetrics.