There are several ways to determine the gestational age:
1. By date of last menstrual cycle,
2. By ovulation
3. According data of ultrasound,
In this the specialist will be able to help you. At home, you can use the following method: Remember when did you have last menstrual cycle. First day of last menstrual cycle, is the first day of your pregnancy. From that day you will count weeks, not months. To calculate the date of birth, you need from the date of the last menstrual period take away 3 months and add 7 days, which corresponds to 40 weeks of pregnancy. But you should not forget that the pregnancy is often not possible to calculate with the help of calendar, especially if the woman has irregular menstrual cycle.
