Are HCG test shows positive is always leads to pregnancy?

Q : I have 2 weeks delay in period. urine pregnancy test (HCG) done several times in different days shows that i am pregnant.according to LMP it should be 6 weeks+. but during ultrasound doctor couldn t see sac or fetus at all not in uterus and not in tubes. she advised me to do beta hcg blood test too. is it possible that if test shows positive that i am not pregnant but have some other gyno issues to investigate? is it always HCG shows only positive pregnancy? Thank you
A : Hello Yes,positive urine test indicates pregnancy.If your calculations are right,then at 6 weeks there should have been a fetal pole.If there is no intrauterine sac then ectopic pregnancy is the next possibility.For several tests to be false positive is highly unlikely.Do the beta hcg blood test and also get a second ultrasound with a different doctor.