I Received My 1st Xolair Shots Three Weeks Ago. While

I received my 1st xolair shots three weeks ago. While it has helped my hives I have gained 9 pounds in the last 3 weeks. Will I continue to gain weight as I receive my xolair shots every month? I was so excited to get off prednisone and have dropped 20 lbs. Now its coming back. I work out 3 days a week. This is quite discouraging.