What does this mean?

So I was at my Dr appointment today. My Dr puts the doppler under my belly button to start looking for the heartbeat. He's moving it everywhere and isn't finding it. I'm panicking of course. Finally he moves it way up above my belly button and finds it. He says, "Wow. I didn't expect to find it all the way up here this early." So I'm looking online and reading that if my uterus is higher than expected then I may be farther along than I thought. Problem is that I KNOW when my last period was. I even know the exact day we conceived, because my s.o. went out on back surgery and we hadn't been able to be together sexually before then. Is there anything else this could mean or is it no big deal?