Carvalho, who joined the principality club from Real Madrid in July after his contract with the Spanish club expired, has featured in all four of Monaco's games so far this season.
The Ligue 2 champions sit top of the table with three wins and one draw, but face some difficult games in the coming weeks, including a trip to title holders Paris Saint-Germain on September 22.
Carvalho has been delighted with the early form shown by Claudio Ranieri's men, and is hopeful that they can continue to develop.
"Our first results have been positive," Carvalho said. "I feel good in the team and, above all, I feel good physically.
"I had a good pre-season. When the body's fine, mentally things are fine too. I feel useful to the team and enjoy playing as much as ever.
"It's a great start and it wasn't something that was easy to envisage given all the movement in the close season. There's a lot of quality here with experienced players and young promising players, but that's not enough to make a team.
"We're still building our team and it's great to already be picking up wins and points. That's the best fuel for our confidence.
"What I'll retain from the opening weeks of the season is the great spirit in the squad and we're all moving forward together."
Carvalho admitted that he had been left slightly frustrated by the timing of the international break, but believes that the rest could be of benefit to the squad.
"I would have liked to have carried on because the team is going well and personally I feel very good physically," he added.
"But this break is welcome after all the work put in in the last two months, generally in the extreme heat. It allows some players to recover from minor niggles."
Monaco face Lorient on Saturday at the Stade Louis II.
