Pregnancy Due Date to Conception Date: A Simple Calculation

To calculate the date of conception, we need to subtract 266 days (the average gestation period) from the due date. Counting backward from May 15, we get:

May 15 - 266 days = November 10

Therefore, the approximate date of conception would be around November 10. However, it's important to note that this calculation is an estimate and the actual date of conception may vary depending on individual factors and the specific menstrual cycle.