The Germany international arrived at Chelsea from Bayer Leverkusen at the start of the season in a deal worth £75.8m - the Blues' second-most expensive signing of all time.
Havertz has failed to carry his Bundesliga form over to the Premier League, however, managing just two assists and one goal in 21 appearances.
"It's been a tough season. I know things haven't been going smoothly," he said after Germany's 1-0 win over Romania on Sunday.
"But that's normal when you first go abroad. It takes half a year or longer to adjust.
"Things are going well right now so I don't want to overthink those negative impressions from the past. I am positive and hope the next weeks will be every bit as good."
Chelsea's first game back after the international break is a league clash against West Bromwich Albion on April 3. body check tags ::