Pregnancy begins when an egg is fertilized by a sperm.
These levels can be measured during the pregnancy to determine whether the pregnancy is progressing normally.
After pregnancy is confirmed, the woman’s doctor asks her when her last menstrual period was.
The doctor calculates the approximate date of delivery by counting back 3 calendar months from the first day of the last menstrual period and adding 1 year and 7 days.
For example, if the last menstrual period was January 1, the doctor counts back 3 months to October 1, then adds 1 year and 7 days.
But the second h CG detection strip uses the hormone to estimate the length of the pregnancy based on time since ovulation.