All of the uncertainty certainly is interesting, to say the least. You want to settle into being happy and excited about being pregnant, but it's like there's another hurdle you have to go over and after you get past that one, another hurdle shows up. I am just behind you (had day 5 transfer on July 9. My u/s is not until August 9 - should be on the 8, but clinic doesn't do u/s on Mondays).
I am incredibly exhausted too and have had nausea, although none today. Also a little light cramping that has decreased.
Looking forward to hearing about your u/s.
All the best to you!