I want to ask my stepmom and dad to at least consider having a baby. any help?

after a couple of days of thinking she was pregnant i found out today that my stepmom isn’t really pregnant. realizing that she wasnt having a baby got me a little sad. my dad and i have a strong relationship and im able to tell him anything ((same goes for my stepmom and me)) but i just don’t know how to bring up the question. any help?