feeling the pressure not to gain..

I was 207 when I got pregnant and dropped to 190 during my first trimester due to morning sickness.. I made myself a personal goal of not gaining more than 30lbs my entire pregnancy, which I thought was reasonable and healthy.. I had my Drs appointment at 21 weeks yesterday and I have gained 4lbs back in 3 months, which he says is great!(baby is healthy weighing 14oz) He told me he only wants me to gain a total of 20lbs my entire pregnancy! That's 16lbs over the next 19 weeks, is that reasonable? My bmi has me listed as obese, but I am just a curvy size 14..