Does anyone else think 18 months post op is too soon?

My heaviest was 450 lbs which a truck scale told me so in 2007 I decided I had to change. I lost about 125 lbs over the next year but in 2009 I got pregnant with my first child and took the best care of myself I knew how which lead to me losing weight and getting down to 280.  But that was short lived and with in about 4 months I was back to 325 and pregnant again. I lost again but again was quickly gaining when I asked for help from my doctor.  I met my bariatric surgeon for a consult on June 26 2011 and on September 13 2011 I had gastric sleeve.  Since then I have lost 134 lbs and had another child.  Currently I eat "Clean" and do not take any type of medication or vitamin.  My body is healthy and strong, I get all the vitamins and calcium I need from my diet and my doctors are happy with my success and lifestyle changes and so am I.  My goal was always to be healthy so I wanted a healthy weight based on BMI.  My goal weight was 164lbs.  I surpassed that and got to 150lbs but was too skinny and now am comfortable around 160.