Weight gain.

I'm 28 weeks and have already gained 43 pounds. Is that to much? I'm going to breast feed and people tell me it'll just fall right off. I was 127 pre pregnancy. I lost weight and went to 119 during the first trimester. And now I'm 162. I gained it all in the second trimester and it scares me. Should I be expecting to be 200 by time I give birth?