The ideal amount is 25-35. By the last 2 months or so you'll be gaining a pound per week. Just be careful I don't think its too much personally. If your pre pregnancy weight is normal you'll gain more weight than an over weight person who will gain very little to nothing.
I'm 24 weeks and have gain 13 pounds, my doctor is not concerned. I think you are normal. Don't worry.
I'm 27 weeks 4 days and I've gained about 25lbs already. My doctors are not concerned at all. Everything is going great and this is my first. I think everyone is different and we all don't fit the norm.