No sè si significa q sòlo llegò a 20 y aùn no se determina embarazo o sòlo esto es una explicaciòn q ponen en todas las pruebas: In normal pregnancy 20 mIU/nO hCG is reported to be present in both urine and serum 3 to 3 days before the first missed menstrual period.hCG is not normally detected in the urine and serum specimens of healthy men and nonpregnant women.