my Gynae told me usually ppl went to her from week 6 onwards... I went during week 5, was a little early, but its always good to know how your pregnancy is developing, if the gestational sac is in the right place, initial stage is very important. Your Gynae will also start prescribing you follic acid for u to start taking. :)
Once youve tested positive, you can start fixing appt with your preferred hospital or gynae.