AITA for telling my sister to fuck off with her scientifically accurate term?

I'm five months pregnant and told my family a few weeks ago. My sister wasn't happy for me and told me she was concerned about my "geriatric pregnancy." I told her I'm under forty, and it isn't a "geriatric pregnancy" and that I didn't need her concern, because my OBG and I had it covered. She still wasn't happy for me, but it is what it is.

At Easter dinner she again referred to my pregnancy as geriatric when talking to the family, and I again corrected her. She said "sorry, but if you are over thirty-five it's geriatric." Other people weighed in, mostly disagreeing with her. She pulled up an article on her phone saying thirty-five and over is a geriatric pregnancy. My aunt laughed and said that is idiotic. She said at this rate everyone will be either too young or too old to have children, since twenties is too young and thirties is too old.

My sister said that she's using the scientifically accurate term, and it isn't her fault if it upsets me. I said "well you can fuck off with your scientifically accurate term, because we all know you are just trying to make me feel bad." Someone changed the topic, but she didn't talk to me the rest of that Sunday. The next couple days, she sent me several links to articles about geriatric pregnancies, so I blocked her.

My mom called me this morning and asked if I blocked my sister. I said I did temporarily, because she was spamming me. My mom said "grow up and make nice with your sister. What you did, using profanity on a holy day, was just as bad. You're going to be a mother, act like one."

Was I the asshole, and do I owe my sister an apology?