KKH Ultrasound how often?

Hi glowing mommies, I went to KKH at 6 weeks for first check-up. They did US but gestational sac was empty. They said it might be too early to see anything and asked us to come after 2 weeks. So went back again at 8 weeks and they did US again but this time they could see the fetal pole and heart beat also detected. Now the doctor is asking us to come back again in 2 weeks time to do another scan. When we received the next appointment SMS it is not even 2 weeks it is only 8 days and cannot change appointment also. How often are you being asked to come for the scan during your first trimester at KKH subsidized? 1 st visit at 6 weeks - ~$120 2 nd visit at 8 weeks - ~$120 Thanks in advance for sharing. :) Update: Thanks mommies for all the replies. I called KKH and booked my appointment 2 weeks later instead of 1 week.