Vale took the lead after just 37 seconds at Sixfields when Chris Neal's long ball evaded everybody and Doug Loft pounced to easily slot his eighth goal of the season into an empty net.
Ben Williamson scored the second after 73 minutes after heading in from two yards out.
Jordan Clarke headed in substitute Mark Marshall's free-kick with 10 minutes to go before Callum Wilson's solo effort in the 90th minute completed the comeback and secured a point for the Sky Blues.
And Pressley believes his troops dominated the game but was pleased with their fightback after finding themselves 2-0 down.
"I think it should have been a victory and that's the bottom line," Pressley said.
"To find ourselves 2-0 down in a game that we completely dominated is incredibly frustrating.
"We were so much in control of the game and we had a number of good opportunities.
"It was the least the team deserved. The pleasing thing for me is that we were a really young team out there. And the young team at 2-0 down didn't compromise the philosophy, we kept passing, we kept probing and in the end, as I said, we got the least we deserved.
"We're a really good side who create a lot of chances and the way the game went the point was well earned."