I can't stop wanting a baby :(?

I'm 19 years old and for some reason I want a baby really bad. I know deep down that now isn't the time, as I am in college still and plan on going to grad school and get an MBA and have a good career (I want to be involved in business). All of this is very important to me but for some reason I want a baby SO BAD. Like if I'm around a baby for an extended amount of time I kind of pretend it's mine and I daydream about having a baby. And I imagine being pregnant. I'm not even in a relationship right now! Back when I was dating my ex, I was always a little disappointed when I got my period because it meant I wasn't pregnant (even though we used protection). How can I get over this?