In a game of few chances at the Riverside Stadium neither side could find a breakthrough and were forced to settle for a point.
Ferguson told reporters: "We weren't at our best, particularly in the first half, but once we got to grips with it we did well.
"When not at your best you have to battle away and we did. That's seven unbeaten now and another point so that's not too bad.
"We'll find out at end of the season if that was a good point or not."
Peterborough are 23rd in the Championship, one point adrift of safety.