Weight Gain

Help! So with my first child I was super young and was around 128 pre pregnancy and gained around 30 pounds and got super skinny right after. Well now it’s 6 years later I am 158 (but I am 5’9) and am pregnant with baby #2. I am terrified to get super big this pregnancy. My goal is to only gain 20 pounds but I know that’s more difficult with more babies you have. I don’t drink Coke’s or have terrible eating habits before baby and definitely have made better choices since I found out but I still scared of the inevitable😩