Hi Haru, it's the norm. When you go to gynae about 8 to 9 weeks, it's just the right timing to do the dating scan to date the pregnancy. There's nothing else a gynae can do for you between now and 8 to 9 weeks.
At about 6 weeks, you can see a sac if you go to gynae, but it is just a dot on the ultrasound. You can't see the bb, you can't detect the heartbeat (heartbeat only detected usually about 8 weeks). You don't need an ultrasound unless you have cramping, bleeding, to confirm that the pregnancy is not ectopic (it is not ectopic if can see the sac). If there are no factors suggesting ectopic preg, there is no need for the ultrasound.