I been going with this boy for 4 years he's 22 and I'm 20 I really want a baby but he don't as he said he wants to wait. I feel live we nothing going anywere. I always want a baby from the age of 18

Wanting a baby and needing one are two different things, and getting pregnant by someone who does not want one is not fair to the guy or the baby. Children should be born to couples who really want them and can afford to take care of them.
Get a puppy or a kitten, but don't have a baby at 20 by a guy that does not want one and a relationship that is going nowhere. That is a bit selfish and childish.

Well I recommend getting married first. Wedlock has a bunch of benefits to you and the kid. If he isn't ready give him time. You 2 are pretty young...

Before you start trying though...

Can you support the kid financially..
What's your living situation...
Would you have support...