Could I get fired

Im 26 weeks and i still havent told my boss that im pregnant yet but i did recently get sick and bring my doctors not and it was saying different things about pregnancy im planning on talking to them soon about taking maternity leave and i wanted to know will i get fired for telling them this late my co workers know i live in nc as well so idk if all policy's are the same ive bever been in this situation i started working after i had my first daughter so the whole working while pregnant is sort of new and no this not my first job I've just never worked on a job while pregnant