Use the first day of your last menstrual period as the starting date
Count the number of weeks since that date
Divide the total weeks by 4 to estimate pregnancy months
Remember that pregnancy is usually measured in weeks, not exact months
4 weeks is about 1 month
8 weeks is about 2 months
12 weeks is about 3 months
16 weeks is about 4 months
20 weeks is about 5 months
24 weeks is about 6 months
28 weeks is about 7 months
32 weeks is about 8 months
36 weeks is about 9 months
Confirm the estimate with an ultrasound or healthcare provider