Sorry to hear you're going through all this uncertainty.
I was always under the impression that a transabdominal scan really couldn't show anything until at least 8 or more weeks and that's why they do a transvaginal.
I had a similar experience, I had some bleeding (which I assumed was a period but it never really increased as you'd normally expect which is why I tested). I had another bleed at 5 1/2 weeks so went to the doctor. This is my second pregnancy and I knew EPAC wouldn't see you until 6 weeks so just wanted to get the ball rolling really.
Anyway, they gave me an appointment to check it was in the right place due to the bleeding. I had the scan at 5+5 according to my dates and they could see a 9mm gestational sack but nothing else, right at the very end she said she could maybe see a possible very feint yolk sac but couldn't be sure and diagnosed a pregnancy of unknown viability and booked me to come back in a week, no sooner as they needed time to see what happened.
I spent that week googling to see what the usual outcome was with a sac of that size despite knowing it wouldn't affect my outcome! (I did discover the sac would have to be significantly bigger with nothing inside to diagnose it as non viable)
A week later I returned expecting them to say there had been no change and to my surprise I now had a yolk sac, fetal pole and heartbeat, baby was measuring at exactly 6 weeks size even though according to LMP I was 6+5 by that point.
My point being a HUGE amount changes in a week, especially around the 5-6 week mark. The EPAC at my hospital wouldn't even contemplate a transabdominal scan so early in pregnancy due to how little you can see.
It sounds as though things definitely could still be progressing normally, especially as all your bloodwork was as expected. Have you had any more bleeding? If not I'd take it as a good sign and hopefully in a couple of weeks things will look completely different. Using LMP is not completely accurate and a couple of days makes a huge difference so early on. Is there no way they'd see you after a week rather than two?
In terms of a full bladder I would have thought that if it was causing any issue they'd have asked you to empty it and then they'd try again.
Fingers crossed for a positive outcome, I know the waiting is horrendous, you just want to know one way or another but don't give up hope!!