Pompey came from behind to lead 2-1 but conceded an equaliser when Lindon Meikle tapped in.
For Ferry, the draw was a disappointing result.
"It felt like a defeat. We played great in the first half and deserved a 2-1 lead, we'd opened them up and had a few chances – but the second half was so disappointing because we never really created any chances," he told The News.
"It was all them lumping it forwards and us trying to defend it but there is only so long you can do that for."
Pompey are 11th in League Two with five points.