Concerned with too much weight gain

I started this pregnancy at about 173 lbs and a BMI of over 30 and I'm extremely anxious about gaining too much weight! I feel really guilty if I eat too much (which I'm not!!) I'm not eating more than what I used to before my pregnancy but for some reason I feel like it's too much 😕
I was just crying to my husband after seeing all these thin pregnant women on Pinterest. I'm only 8 weeks but I feel HUGE! 
Any women start off with a little too much weight?