When to go polyclinic to ask referral to hospital for pregnancy?

Hi mummies, usually at how many weeks u go to poly to ask for referral to hospital for pregnancy? For my 1st child i went to poly when we are 10 weeks alongs as we test for the pregnancy kit quite late. With my 2nd child, i am under specialist clinic in KKH due to previous miscarriage so i can walk in straight in the clinic to see the gynae. But now with the coming 3rd one, im not sure when is best time to go? 1st and 2nd we went to kkh. This round we intend to go nuh.