The Spaniard has overseen goalless home draws with Manchester City and Fulham and a 3-1 defeat at West Ham after taking over from Roberto Di Matteo at Stamford Bridge.
When asked about his future after Saturday's Upton Park reverse, he said: "No. I am not 100 per cent. We didn't win today - that is the main thing.
"I would say it depends on the things that we can do on the pitch. So if we improve on the pitch, it will be easier for everyone."
West Ham boss Sam Allardyce, whose side trailed 1-0 at half-time before a second-half fightback, believes Benitez needs to win over the Chelsea fans in order to succeed.
He said: "You can't manage a club if the fans are not behind you. It just won't happen. And the only way you get them on your side is by winning games.
"If you're winning the fans will always back you."