The pregnancy calculator below uses the reported last normal menstrual period (LMP). Because of that, it is only an estimate of weeks of pregnancy (gestation). A computerized calculation does not constitute medical advice. Missing a period does not necessarily mean that you are pregnant. Having a period does not mean you are not pregnant. Only an exam, pregnancy test, or ultrasound by a physician can confirm pregnancy and approximate length of pregnancy. The calculator is only a guide. Therefore, one should not rely on it for weeks of pregnancy, conception date, or due date.
To estimate the length of your pregnancy, enter the first day of your last period and then press 'calculate'.