Plan B?

So me and my boyfriend had sex last night and he didnt pull out and then said well have to get plan B in the morning..... Weve talked about having kids but not just yet cuz were kinda young ( 21 and 22 ) and his grandparents would freak cuz were not married but i really want a baby....were steady financially, all my friends are having kids and still in college and his parents always talk about "when you two have kids....." But idk im on the edge i have 48 hours before my time is up to decide. I really need input and/or support anything advice helps