Your not alone some women just gain a lot of weight during pregnancy. With my first child I gained 67lbs. I'm 5'1 feet tall and weighed 155 before getting pregnant with baby#2. I am now 36 weeks and at my last appt I had already gained 54lbs. My doctor already checked me for gestational diabetes and he is no longer concerned so I agree unless your doctor is worried about your weight gain I wouldn't be either.
Not unless your doctor is. It's probably fluid retention