23 weeks and losing

I will be 24 weeks this friday and I've gone from 283 to 268 since I've been pregnant. I got all of my fluid taken out at 16 weeks because of being too tight and also was having trouble with my gallbladder (which I had to have out at 18 weeks). Needless to say I've had a hard first pregnancy. My question is, is there anyone else that really hasn't gained any weight yet and are close to their third trimester? If you are in the same situation then are you worried? I haven't got in trouble with the doctor because they say ill gain it in my third and I hope they are right.