How can you tell how far you are in a pregnent?

See doc, get u/s: Generally count weeks starting from the first day of your last period, if you know when that was. Generally by 16 weeks, baby bulge is halfway to umbilicus and by 20 weeks baby bump goes up to the navel. If you have not, please see a doctor. An ultrasound is your best dates measurement if not sure about last period. If you want a healthy babe, please get prenatal care.

Pregnancy Wheel: You can find online many sites that will let you put in your last menstrual period and it will tell you your due date and how far along you are. If your periods were irregular or unknown, an ultrasound can be done to measure the size of the fetus and that will correlate with your current gestational age.