OBGYN appointment every 2 weeks?

So I had my first appointment at 4 weeks 4 days, and didn’t see baby at all. Got my HCG levels taken and they well over doubled within 2 days. I had another appointment 2 weeks later and they saw the baby but didn’t really explain much to me, they just said that the baby looks exactly 6 weeks 4 days and my dates were totally correct. They scheduled another appointment for 2 weeks later. I’m just wondering why I have an appointment every 2 weeks? I understand the second one to see if the baby was there, but why another one so soon? Also, does everything look normal with my ultrasound? I really wish my OBGYN would explain things to me a little more so I didn’t find things to randomly worry about!