Craig Mackail-Smith looked to have secured all three points for Posh in stoppage time but his goal was ruled out for offside.
"I thought we deserved three points over the 90 minutes," Ferguson said after the 1-1 draw.
"You always need a bit of luck and we are just not getting it at the moment. But there is no time to feel sorry for ourselves.
"As long as we keep putting in performances like that then we will get the wins."