I really feel you on this, the wait after a high-risk FTS is just so hard and I can only imagine how anxious you must be feeling right now. I don't have direct experience with NUH specifically, but from what I know of KKH, no news does tend to mean the results are reassuring, and clinics here usually do prioritise calling quickly if something needs urgent attention. That said, since you haven't been able to get a response and your next appointment feels so far away, it might be worth walking into the clinic in person to ask them to pull up your results, sometimes a face-to-face request gets things moving faster than calls or emails. Hang in there, you are doing all the right things by following up, and I hope you get your answer very soon.