Weight Gain Question!

Racheal • First Time Mommaa | 17 &&&' Pregnant | Due Sept 15th | Blessed With Our BabyGirl Leiana Ann Pritchett💖👶🏽👨‍👩‍👧😍🎀
Someone had mentioned that I weigh to small to be almost 24 weeks .. What do you think ?
Before my pregnancy I weighed bout 115 . Now that I'm pregant I weigh 131 and I'm 23-24weeks pregnant . 
Should I be gaining more weight ? Or have I gained too much weight ? Or am I just average ? 😓