Why am i so broody help!! ?

Ok so im 19 years old I've been a real party person for a few years now but for the past few months I've been really wanting a baby, I know ifs silly at my age because im only 19 but props about 6 out of my 10 close school mates are or had babies I've got a 8 month old baby cousin who I adore too. All I really want is a little baby!! Why the hell am I this broody?