It’s normal for first time mums to have small belly because everything is not stretched out yet. I have a small belly (my colleagues didn’t know I was pregnant till late 8 months, some only saw my belly the day before I went to induce *imagine their shocked faces*).
And yes, hard to sleep is normal, however if you’re worried, do raise your concerns to gynae during your next scan (they know your condition best!).
Congratulations and wishing you a smooth delivery! ☺️