Teddy was nervous. No, that was an understatement. He was terrified. The more he thought about it, the more he felt scared. Nymphadora Tonks was here. She was alive. His mother was alive. The mother who he'd only seen pictures of was soon to be in person. It was practically unthinkable. He'd met Cedric Diggory the day before, but it was nothing compared to what he felt with the idea he was meeting his mother. His mother.
He just couldn't wrap his mind around the idea of meeting his mother in person. Grandmother Andromeda, Harry, Ron, Hermione, Mrs. Weasley... they all had told him a great deal about her. They told him what an amazing person she was, how she was brave, strong, and beautiful. But hearing those words almost meant nothing now. He was going to be able to form his own opinion of her. He didn't think it'd be a different opinion, but an opinion based on what he knew he met in person, not found out in stories and recollections.
Standing outside the door of the flat, he just took a deep breath. On the other side of the door was his mother, alive and breathing. Not that she knew who he was, actually. He was going to be a stranger to her, and even more so. Taking another deep breath, he raised his hand and knocked on the door. It was now or never.