How would you handle this?

Here’s a little back story... like 3 years ago my bf mother did not like me at all for no apparent reason. She was always judging me and giving me the side eye. Fast forward to today, her son became my daughters daddy and my fiancé lol. My relationship with his mom got a whole lot better too. I’m even living with her while my fiancé stays at a military base. (We plan on getting married soon and moving out over there). Anyways she was constantly telling me to get on birth control that it wouldn’t be a good idea to fall pregnant again that I won’t be able to do it. Which I think it’s not even up to her to tell me what to do with my body so I never did. She kept nagging me about it up to the point that before my fiancé came back home from deployment she dared to ask if we will be having sex!!!! 🤯 like wth! That made me super uncomfortable. I hated when I was on birth control so I went with just using condoms. And well I ended up pregnant again and with me living in her home I feel like I need to tell her this. But I’m afraid it’ll destroy what we already have. Me and fiancé are 22 so we’re not kids either. I was planning on telling her until we move out but that’s probably not happening soon since we still have things to do before that. This is more of a rant 😅 I’ll probably figure something out with fiancé but it’s been so stressful.