Pompey returned to winning ways with a 2-0 victory against Accrington on Saturday, to stay in the play-offs.
"We're always talking about the run of games ahead," Stevens told BBC Radio Solent. "We've all got to come together as a team, and as a club, and push on."
Portsmouth are four points from third-placed Carlisle, with a game in hand.
"It's now or never for us," Stevens said. "February is a big month and if we can get as many wins as possible, we'll see where that takes us.
"We got beaten in the two previous league games before Accrington, and there was a lot of pressure on coming into this one."
Paul Cook's side have two home and two away games before the end of February, including hosting Carlisle on 25 February.
Portsmouth defender Enda Stevens believes it is "now or never" for his side's push towards the automatic promotion places in League Two.