How can you tell if you are in the early stages of pregnancy? If your menstrual cycle is regular, start counting from the first day of your last period and see how many days you have until now, if you are not more than 7 weeks pregnant, you are in the early stages of pregnancy. For those who have irregular menstrual cycles or even long menstrual cycles, if you can check the signs of pregnancy with the early pregnancy test strip, but cannot tell how long you are pregnant, you need to go to the hospital for an ultrasound examination to determine the date of pregnancy based on the size of the gestational sac, the germ or the fetal heart on the ultrasound examination.