Based on ultrasound, the uterus is anteverted measuring 5.5 x 3.0 x 3.9cm the endometrial echo measures 0.5 cm in thickness. is it normal?

Was this ultrasound: done for routine pregnancy? IF so, you are probably early on in your pregnancy. If it was done for GYN reasons, e.g. irregular bleeding or untimely bleeding, then it depends on what your normal situation is. Are you on birth control pills or implants? Do you have an IUD or planning on one? These measurements can be normal in the right setting, or not.