Might need bedding in a bit......find an empty road/car park.build up speed, take hands off steering wheel or hold lightly and apply the brakes ( no H+S sh*t here in the red household :lol ) if it pulls to the side its not balanced, pull to the right you need to look at the nearside caliper, offside if it pulls to the left...if it was my car I would run it around for a few days to let the new pads bed in

One, is never going to be enough.....