Congratulations Jay! My avatar is a reminder of my first born. I adopted the baby with the hammer in honor of my wife's pregnancy and eventual delivery of our first daughter. I have had this avatar for seven years. I now keep it for our second daughter who is currently still in diapers, but soon won't be. I have considered getting rid of the baby with the hammer. It is a little distracting. Perhaps when our youngest is out of diapers, I may consider something else.
You are pretty young to be a father. I don't know what kind of father I would have been at 18. Probably not a very good one. I was in my forties when the first was born. I know that I am a better father now than I would have been then.
Give your children plenty of attention and love. And never, ever, shirk from diaper duties. It is truly a great time to bond; and imagine if you were in a stinky mess and no one wanted to help you. Diaper rash is painful and most times avoidable.
Again, congratulations and I hope for the best throughout the pregnancy, the birth and beyond.