My girlfriends car has the same problem right now
My g/f car did that too. I think a g/f thing, they warp rotors like they are going out of style. Her's were warped so bad I could feel it with my hand.
Brake job was also recent, so I just did a rotor swap as the pads have barely been broken in.
Midas did those, I think they put economy rotors on or something. Didn't even bother calling them to warrenty it, just coughed up the $60 for 2 new rotors and everything is fixed.