Is it possible that they could not see anything in your uterus because you are only four weeks pregnant?

At four weeks pregnant, it may not be possible to visualise anything in your uterus on a standard ultrasound. This is because the embryo is still very small and the amount of tissue present is minimal. Transvaginal ultrasound, which involves inserting a small probe into the vagina, may provide a clearer view and allow for earlier detection of pregnancy. However, even with a transvaginal ultrasound, it may be difficult to see anything conclusive at four weeks. If an ultrasound does not reveal any signs of pregnancy, your doctor may recommend repeating the ultrasound in a few weeks to confirm or rule out pregnancy.