I'm pregnant and my boyfriend wants me to get an abortion but i dont want one what can i do to change his mind?

i just found out im pregnant (5 weeks) and im 18 me and my boyfriend have been dating for 3 months and we really do love each other but he wants me to get an abortion because we cant afford a baby and our lives would change alot, and i agree with him but i cant bring myself to get an abortion it just not for me. i have been crying all day thinking about it. i told him i wanted to keep it at first before knowing how he felt. he tells me we can do whatever i want but i know he wont be happy if we keep it. because after he says lets just kep it and he seems excitied about it i ask him if thats what he really want and he just says thats what you wan. i dont know what to do please someone give me some good advice.