Helllllp

So, recently my boyfriend and I have been talking about getting pregnant. Well , I currently weigh 140 pounds and feel like I am overweight and I don't want to be pregnant and gain a ton of weight. I am already SO self conscious. Also, I am absolutely terrified of giving birth for some ungodly reason. I know all of this sounds incredibly strange; but i just wanted to know if anyone else feels this way or someone who can talk me out of the funk I'm currently in.... I know gaining weight and giving birth will all be worth it when I hold my baby, I just don't know why I feel this way.