I don’t know what to think

My boyfriend and I are having a pregnancy scare. I love kids I love being around them but right now I don’t know if I want one. Last week my friend had went to the mall and he saw me playing with a kid he said something like « you will be a good mom » but I just ignored it until two days ago when I told him that I’m late and he told me « we better get ready before you get to term » I he likes to joke but this one wasn’t funny at all. I don’t think I’m ready for that I even questioned our relationship. I just want to do my master and work before all the baby talk. Am I an horrible person not to want kids with him? Or even rethinking about having kids at all? ( I know people dream of having kids and I’m so sorry for being selfish)