The Blues legend told Sky Sports: “Performances and results will define how long I am here.
“It is very easy to be negative after losing 4-0 but there were a lot of good signs during the game against Manchester United.
“As for the performance against Liverpool, I think we were the better team against one of the best teams in the world and probably deserved to win on general play. This is something we should be proud of.
“We need to use that. Hopefully, it will give us confidence about what's ahead. What I have felt in the six weeks that I have been here is that the players are a good group and they have a lot of spirit. We saw that against Liverpool in the dressing room and on the pitch. That is what you want to see as a manager because it gives you the chance to work
Lampard has reiterated that he was under no illusion as to what he was letting himself in for when agreeing to head back to west London.
He added: “Things surprise you in football management every day but the situation has been exactly what I expected.
“I knew about the transfer ban, I knew Eden Hazard had left the club, I knew we were losing two strikers in Alvaro Morata and Gonzalo Higuain and I knew we couldn't buy anyone. I knew we had five or six major injuries.
“I knew all that but the last thing I want to be is negative. I want us to be competitive this year and we still have a strong squad. We have to be a bit patient because those other factors are there. But that doesn't mean we can't go out there with that competitive head on and challenge in everything that we do. My job is to focus on the task at hand.”
Lampard has taken the reins at Chelsea from Maurizio Sarri and insists that, despite questions being asked of the Italian at times last season, he will not be looking to make too many tweaks to tactics and personnel.
The ex-England international said: “I certainly won't be changing things for change's sake.
“But where there are ideas that are different, I have to be strong in those and stick to what I believe will take the club forwards on the pitch. The players have to come along with that because we want to be successful and that takes a lot of hard work and being together as a group.”
Chelsea are back in action on Sunday against Leicester, with Lampard leading his side out in a Premier League game for the first time at Stamford Bridge.