you can wait for a few more days and see if they contact you or send you any appointment notification otherwise you can also try calling them. Depending on the date they give you, if it's nearing the end of your first trimester then it's better for you to do the first trimester test in a private gynae clinic first then you can bring the test results along to your nuh appointment next time. Regarding the folic acid amount, you can ask the gynae if you may continue this amount when you go for your appointment.
You can always call NUH central appointment hotline to book yourself an appointment. Usually much quicker this way than passive waiting for them to call you. Tell them you’ve got a referral from the Polyclinic and would like the earliest available appointment possible. Hope this helps, and congrats!!
Congrats firstly. I’d recommend while waiting to fix an appointment with NUH, go to an outside private clinic for a first visit scan to check on the pregnancy.
You can call NUH and get a consultation as a private patient. It will cost more but a doctor will see you sooner. Good luck!