Is my embryo 5 weeks or 3 weeks into development?
“How far along” you are goes by the first day of your last period. I know, it’s silly considering there isn’t even a baby until you ovulate (which is two weeks AFTER your period). Technically, your baby began life and started developing the moment the sperm and egg met, so 3 weeks ago. But doctors and everyone else measures it by the first day of your last period, so it’s 5 weeks old.
You are 5 weeks pregnant since doctors count from the first day of your last period. But your baby is only 3 weeks along, since doctors generally assume that you conceive 2 weeks after your last period. Depending on when you ovulate, your baby could be 4 or 2 weeks old – basing your pregnancy on your last menstrual period (LMP) date is a generalisation. That’s why you are considered full term at 38 weeks, and doctors will let you go up to 42 weeks if you have not yet gone into labour.
