The Blues striker scored twice during the 3-1 home win against Sheffield Wednesday on Saturday, his third goal in the last two games having scored the crucial winner in the 1-0 win against Crystal Palace in midweek.
"I've come into a little bit of form, which I'm happy with at the moment," O'Connor told ITV Sports.
"The gaffer [Alex McLeish] has given me a run in the team which I'm really happy about.
"We've got a fantastic strikeforce at the club and so you've got to be on your toes.
"You've got to do well when you get into the team and I've managed to do that in past couple of games."