The Poland striker, 37, is off contract at the end of the season, though negotiations over a new deal are yet to kickoff in earnest.
Speaking with the Athletic, Lewandowski said: "I don't know, I have to feel it . For now I can't say anything about what I'll decide because I'm not even 50% sure which path I want to take.
"With my age and experience, I don't have to decide now. Maybe in three months' time I'll have to, but even so, I'm not stressed. I need to start feeling it so it will be easier when we talk about my future."
Whatever the decision, Lewandowski takes away many positive things from his time at Barça.
"Being at Barça these last few years has allowed me to see how much dedication and hard work goes into moving the club forward. There's a great deal of ambition and faith in the future," he added.