Sara, knowing you from what you post here, there's a clear danger you will do too much too soon. When your doctor said "TAKE IT EASY" I promise you he did not mean "see if you can exceed 500 watts".
On this subject I know what I'm talking about. Less than two years ago I too had laparoscopic surgery - appendix rather than gall bladder - and like you I felt fine afterwards and was back on the bike in a week. That turned out to be a mistake, I had post-operative pain for four months, intermittently, sometimes quite severe. I'm pretty confident that my over-enthusiasm ended up prolonging my recovery.
Next season is a long way away, you have time to recover properly and build. Take it easy and, for a while, use the powertap to keep your effort levels down to a sensible level, not to set any PRs.
And welcome back, btw.