Weight gain.

I am annoyed because I didn't understand this before I got pregnant etc. At my first appointment I didn't even own a scale yet. They asked me my pre pregnancy weight and I basically guessed. Now I am consistently near the top of the stupid chart and it's honestly pissing me off. I did fertility treatment for a year and I don't know if I had gained additional weight before I even got pregnant. Once I was pregnant I had to keep eating or throw up. This week I felt good I was consistently around 8 or 9 pounds gained and then within four or so days I gained four more pounds. I'm sorry but now I'm at the top of a chart that isn't really even based of a real weight, just a number I threw out there guessing what I had weighed before. I know it's not that big of a deal but I have never been unhealthy or had weight issues and my body is telling me to eat and the chart is telling me not to and I want to trust my body. I am 5'4, almost 20 weeks pregnant and weigh now 135 pounds. I don't know how the doctor can even find this concerning.