Yes I'm still in school, i haven't told my family, & yes my boyfriend is very supportive..
I don't have an older brother but I can understand why yours would be protective over you. I'm the oldest out of 3 girls and I'm very protective over my younger sisters.
I take it you have not told your brother you're pregnant yet? I think it's a good idea to have a plan in mind before you tell anyone. Are you still in school? If so, do you plan to continue your education? Is the babies father being supportive of you and this pregnancy?
Family members can get upset because they worry about you and your future. If you have a good life plan and stick with it, it will make things so much easier.
We're always here to listen and help if we can.