''If my header had gone in then it might have been us that had gone on to win, but it didn't,'' Mullins told the Monday edition of the Nottingham Evening Post.
''I don't think you could argue that they were the better side over the 90 minutes though. They had a lot of chances and we just couldn't get going.
''I don't think Peterborough were that good . They caught us on an off-day and took advantage. We can't let what has happened affect us and get us down. We have to look forward and move on to the next game.
''We have the Rochdale game coming up next and there is no reason why we can't go there and bounce back with a win.''