When can I start spinning or exercising after breast reduction?

I recently had a breast reduction (30/09/14) which took me from a 34L/M to 36DD. 3kgs of fat were removed from my breast. I'm ecstatic with the results - they have literally changed my life. I was fully active before surgery &trained 4/5 x pw. I'm going crazy being away from the gym. I know it's important not to exercise to soon to avoid ruining the results, I've always found I put on weight easily (I don't drink, smoke &generally have a healthy diet) if I have extended periods of inactivity.