moving too fast ?

Me and my bf have been together for 3 years. we’ve talked about marriage a lot. He recently joined the Army so we’ve been talking about it more. We decided we want to definitely get married and I want to wait till next year around our 4 year anniversary because i want to keep the same date. (it just makes sense to me lmao). So we do live together, it’s a really long story but i pretty much was 17 and had no where else to go and his mom offered to let me stay so long as i pull my weight. which i work full time and also am in online school. anyways fast forward, we’ll be 20 next year. we plan on moving out once he comes home, the beginning of 2022. i love and appreciate and get along with his whole family, but sometimes they make comments that hurt my feelings. So last year, his brother got married to someone he was with for 5 years, they’re 24. everyone told him they were rushing and moving too fast. they ESPECIALLY had a lot to say when they recently found out they were pregnant. i mean the comments i heard people make about his wife behind her back are honestly terrible. i mean even his brother (her husband) constantly complains about her and how he wasn’t ready and pretty much just talks about how he hates his wife 24/7 (he’s VERY immature) they made similar comments to me about how we better not have kids anytime soon, better not move fast like the brother did, etc. which i understand, definitely not when we’re living with his mom. but once we have our own place, why is it anybody’s business ? i know what it takes to have a child, it’s a life long commitment that is NOT easy. I’ve had jobs in child care since 12 years old. anyways the whole point of this is, if and when we have kids/ get married, i do not want to tell his family. The marriage part i definitely want to wait awhileee i mean probably a year or two to say anything. and as for the kid part, he has been asking me to have a kid but i’m not ready yet and told him we can revisit the conversation next year, but if i do decide to then, i want to wait till around the 7 month mark to tell anybody. is this unreasonable? he said he understands but part of me feels bad he wouldn’t be able to share this with his family. i wouldn’t tell my family either, mostly because i don’t really have any, but also because i think that’s un fair. i just really want to keep everything as stress free as possible.