I'm only 18 and dying to have a baby. I hear it'll be harder for me conceive when I'm in my twenties and old?

Notable statement. The brain of a woman is still establishing mature connections until about age 22 (men 25). Take this into consideration when you consider your thoughts.Twenties would only be old if we lived in caveman times when the life expectancy was <30.It would be good for you to consult with an unrelated counselor to find out why you are so focussed on babies. Understand why & then make your plans.
PREGNANCY. At age 18 you just become an adult and still growing. Focus on your education and maturity. There is lot of time to become a mother before age 40 when having a baby becomes complicated. Besides at this age, when love fly out of the window you are left with a baggie.