Why am I gaining so much weight?

So I was 125 lbs when I got pregnant (I’m 5ft 8in). This is technically in the healthy range so i should gain 25-35 lbs. Well, I’m at 25 weeks and have already gained 25 lbs. I struggled with morning sickness in the beginning so I gained normally but noticed I was gaining faster than I should be after the first few months. I decided to pay more attention to what I eat and track every calorie to make sure I never go over. I literally never go over what is recommended and am usually under. I will admit it’s not always healthy food, but I am definitely not always eating junk food and tend to have a pretty well rounded diet. I also have a job where I am on my feet and moving quickly for 6 hours, 4 days a week. On top of that I am cleaning and doing physical activity of some sort at least 2-3 hours a day. There is little to know difference in the appearance of my body, aside from the baby bump, and I am not incredibly swollen or anything. What is the issue? Where is this weight going? Why am I gaining so quickly and what am I supposed to do about it?