do you have to be married to have children?

so i been with my boyfriend for 2 in a half months.. everything is going good but he wants a baby .. i told him but do you want to marry me later on? and he goes yes but it doesn't matter if it goes in the order  i mean i know that because i have family that never been married but yet have 5 kids lol ... But should i be worried if my boyfriend wants babies first ? then married?