Weight gain

S • Married since October 5, 2013. Baby girl born July 20, 2015🎀
I didn't start to actually gain any weight during this pregnancy until halfway. I will be 32 weeks on Sunday, I now see my ob every two weeks and at the last appt she said I had a big increase in my weight of 7 pounds and two weeks later to today I had another big increase of 8 pounds. I'm starting to worry, is it normal to put a big amount on in a short period of time at 32 weeks?