Can someone check my work for me, please.

Question

1.Yesterday he was very busy since he had been fixing the TV from noon.

2. He left for the day before I arrived. He had been waiting for me almost a week. To regret, I couldn't come earlier.
3. When Anna entered the living room, everyone was laughing. Mr. Smith had been telling funny stories for 15 minutes.

Answer 1

All verbs are correct. =)

I would add "my" before "regret" in #2.

Answer 2

Thank you very much

Answer 3

You're welcome!