Is an ultra sound the only way of finding how many weeks pregnant you are?

An ultrasound is not the only way to determine how many weeks pregnant a person is. Some other methods include:

Last menstrual period (LMP) date: This is the first day of a woman's last menstrual period. Adding 280 days (40 weeks) to this date will give an estimated due date. However, not all women have a 28-day menstrual cycle, so this method may not be accurate for everyone.

Blood test: A blood test can measure the levels of human chorionic gonadotropin (hCG), a hormone produced during pregnancy. The levels of hCG increase rapidly during early pregnancy, and a blood test can detect pregnancy as early as 10 days after ovulation.

Clinical examination: A healthcare provider may be able to estimate how far along a pregnancy is based on the size of the uterus and the development of the fetus. This method is less accurate than an ultrasound, but it can be useful in early pregnancy when an ultrasound may not be able to provide a clear image of the fetus.

Fetal movement: Most women begin to feel their baby moving between 16 and 24 weeks of pregnancy. The healthcare provider may be able to feel the baby's movements during a clinical examination, which can help confirm the pregnancy and estimate how far along it is.

In most cases, an ultrasound is the most accurate way to determine how many weeks pregnant a person is. However, the other methods listed above can also be helpful in estimating the stage of pregnancy.