5w6d ultrasound what to expect?

So tomorrow I am having an early ultrasound. I was instructed to drink 32 ounces of water before so I am guessing it’s not transvaginal. I don’t know why they are doing abdominal ultrasound if I am still early. I wonder if they don’t see anything if they will do transvaginal. I had an transvaginal ultrasound last week in the ER and they saw gestational sac. My labs show hcg is rising. Anybody have experiences with ultrasound this early? Should I say something if they say they can’t see anything with the abdominal ultrasound?