This is purely your decision. As a girl who got pregnant at 18, I can tell you now.. if you have a baby at your age, you'll be losing a lot of freedoms you have. I can't even get ready in the morning without having a toddler scream at me.
You have another 20 years to have a family. I know about the urges to have a kid. I took care of my niece for a year when I was 16 and would cry over her not being mine. I wanted to be a mother so badly that it hurt. Once I realized I was too young and needed to live life, I got pregnant. I do not regret my decision, because my daughter has breathed new life into me.. but, for her sake, I do wish I had waited longer. She deserves a lot more than I am capable of giving to her right now. I went through bad post-partum depression. I missed being able to just go outside by myself and spend an hour looking at the stars. I couldn't do that when she was a newborn, because she required constant attention. The smallest of things in your life are changed by a child. Every aspect of your life is altered. My situation is different than yours would be, as I was a single mother for the first year of her life, but.. there would be some likeness too.
I still struggle with it now, even though there's a man in my life who helps me financially and emotionally with the strain of being a parent. Michael and I can't even go out together without planning. I have to make sure I'll have a baby sitter, enough money to pay the sitter, et cetera. Recently, I had to go out of town for a week to get my boyfriend's stuff from his house (He lived in Kansas and moved here for me), and it took over a month of planning to just leave for those few days. I couldn't take her with me, because we were driving back. I had to wait for my mother to get time off work and that was a luxury, I would've had to find a sitter to stay home with her and pay them a fair bit of money otherwise. Before I had her, I up and left home all the time. There's no more room for spontaneity in my life. Also, It costs a lot to raise a baby. I'm trying to get through college now and raise her.. and it's very hard. What's worse is, I too have baby fever again and want another one. I'm putting my wants aside, because I know that it isn't time. Maybe in five years, but not right now.
If you're wanting that badly, make a plan. Give yourself a list of things you need/want to do before you have a baby and have to come home every day and every night to take care of your family. If you like going out with friends, do that as much as you can while you can. The only time I see my friends anymore is when we have play dates. The only friends I have time to see are the ones that have babies. Enjoy your freedom and money. The way I look at it with my baby fever is, if it happens.. I won't be sad about it and I know I'm capable of being a good mother.. but I am not, in no way, trying to have a baby. I'm going to get the rest of my life together before I bring another child into the mix.