It is a very happy thing to be pregnant with IVF, then the expectant mothers start to be concerned, we do IVF and other natural pregnancy is not the same, when is the due date? Let’s take an example to understand this matter. Zhang had her fresh embryo transfer on the 3rd day after egg retrieval, so we should consider her last menstrual date as the day of transfer and subtract 17 days. To be more specific: Zhang’s fresh embryo transfer date is April 22, 2015, so her last menstrual period should be considered as April 5, 2015. And the due date is calculated as the month of last menstruation minus 3 or plus 9, and the day is the first day of last menstruation plus 7 days. Therefore, Zhang’s due date is April 12, 2016 (if the transfer is a 3-day frozen embryo, it is also calculated in the same way). In the case of a 5th day blastocyst transfer, the last menstrual period is the day of transfer minus 19 days. For example, if the transfer date is March 22, the last menstrual period will be March 3. Can you do the math?