need advise

i took a test and it come back postive (both of them) im engaged to the father and love eachother very much, however my family is weird about having kids before getting married and im not sure how to tell them! I was never close to my mom growing up but last year she had cancer and that all changed i hate that it took her getting sick to finally have a relationship with her, but anyway i dont want them (mostly her) mad at me i understand it will be hard for them to understand that this is whats happening and there is no changing it. I'm excited and nervous about being a mother to my child and a step-mom to his three year old little boy who i love as if he was my own! i've always talked about having kids but never really thought about having one now but life happens and here we are (im 18 and he is 22). i just want to know that i have both my parents and his dad supporting us through this journey ...any and everything said will help thanks in advance ladies💕