Last menstrual period "LMP"
This is the first day of your last period. It assumes you have a 28-day cycle.
Ovulation and Conception
This is 2 weeks after the LMP when the cycle is regular and 28-days
Enter a date between your LMP and your EDD to calculate how many weeks you are on that date. Today’s date will tell you how far on you are now.
*If your cycle is not the average 4-week cycle, you can adjust for this. For example, if your periods came every 5 weeks before you got pregnant, you would adjust by booking the ultraounds one week later.