I absolutely think you should do it. A thorough scan is just what you need, and thankfully you have someone who can do it for you without rushing or treating you like a crazy person. I say do it.
That way you can make a more informed decision about the course of your healthcare from that point. You need to see exactly what's in your uterus, outside of it, the whole nine. Then you can go from there and know what you want to do. No one has to know and you don't have to take the OB/GYN that you've been seeing your results unless you think they really need to see them.
If it's a pregnancy, great and if it's not, then you can make a better decision about the next steps and be more prepared. Praying for you, and please, PLEASE keep us updated!
This sounds like a major blessing!