I'm thinking about starting in week 3 ......what yall think

Nope ... have you talked to your surgeon about this?

If you search the site or go over to the fitness area forum here, I think the concensus is 6 weeks out. Your body needs time to heal. Don't forget, you are having 85% of your stomach removed. How well do you want your stomach and incisions to heal? Are you really in that big of a hurry to get the weight off? Perhaps start 3 weeks prior to surgery, take 6 weeks off, and then go full steam ahead.

I started exercising 3 days after my surgery with the blessing of the surgeon. Nothing crazy at that point, just 20 minutes on the elliptical at very light resistance. By 2 weeks out I was doing completely normal exercise which is 40 minutes of cardio 5 days a week, weight training 3 days a week and Yoga every day. I would definitely ask your surgeon since different ones have different rules but I will tell you that I had no issues at all as long as I didn't push myself in those first 2 weeks.

I started at 3 weeks walking 2 miles, 3 days a week. I recently started lifting weights at 7 weeks post op. I also lift heavy weights but not super heavy. I also started running a week or 2 ago and now I'm able to run a mile non stop. My advice is to listen to your body. Good Luck