Gaining weight

Hi ladies I started with my weight of 179lb (5ft) I know I’m obese okay but my first trimester 3 months I lost weight I went down to 169lb I was like omg it’s that okay but my ob said that’s perfect. I’m 32 weeks now I get my appointments every two weeks now but I notice this past 2 weeks I’m gaining 3lb every 2 weeks I’m worried my ob tolled to watch my weight now. But I don’t know what I’m doing wrong all my pregnancy I have gain half a pound or one pound every 4 weeks. I had not change my eating habit I walk and to everything the same I don’t knows what’s wrong.

I started with 179lb went down to 169lb but know I’m 181 lb last week appointment I just weight myself I’m 183lb my next appointment it’s on Monday I’m worried what would happen if I gain a lot more . (Only supposed to gain 11-15 lb )