AITA for not telling my ‘parents’ that I had a baby.

Hi reddit! I never used this app before, but one of my best friends said I should come to here for some advice from people who aren’t ‘biased’. Please forgive me if I ramble or if I don’t explain the situation that well.
For context I(18F) don’t have a good relationship with my parents (52F, 50M), growing up they always kind of favored my older brother more (28M). Probably from the fact they always wanted one kid lol. I didn’t have the best childhood with my parents, starting at the age of 6, I went back and forth to my grandparents(paternal, 69F, 70M) house and their house for a few years before I moved in with my grandparents fully at the age of 10, and even though my grandparents were retired already, they tried their best to give me a nice childhood, even if my parents didn’t want to give me one. Last time I talked to them was over a year ago, during the holiday probably around November, December 2024.
Well in late March of this year I found out I was pregnant (Yes I know i’m young and made some ‘bad’ decisions, but i do love my baby girl and wouldn’t trade her for the world. For the sake of her privacy I’m just going to call her, Baby) I didn’t tell that many people only people close to me and close to my boyfriend. Babygirl was born on December 2nd!
Well earlier today we had a Christmas dinner at my grandparents, where everybody was included, my parents and brother included. I could tell they was shocked to see me holding a baby, let alone MY baby, but didn’t say anything at first, until the actual dinner started, when one of my aunts asked me how Baby was doing, and which i started explaining how Baby has been way more alert, even started cooing lol. Well I guess me explaining set something off in my mom because she said something along the lines of “Why did you keep ‘Baby’ a secret from us.” Which kind of caught me off guard because I replied with “Not a Secret, just didn’t tell you.” That didn’t go over well i guess because My mom started saying I “took away their chance to be grandparents(which is bullshit because my brother can have kids)” and that I was selfish for not telling them. My dad agreed and said it was rude and embarrassing that they had to find out in front of everyone.
I told them straight up that I didn’t feel comfortable sharing something that big with people who barely talk to me and, I just wanted to be left alone and have a peaceful pregnancy.
The table got super awkward, Which did make me feel bad for our family who was just trying to enjoy a meal. I don’t feel bad for trying to protect my peace and trying to protect my daughter but later that night some family members told me that I was selfish for not telling them. My grandparents and my Boyfriend are trying to reassure me that I didn’t have to tell them anything but i’m starting to second guess. So AITA?
(Also before anyone asks, I know how it sounds, taking a newborn out to a family party, but she was only allowed to be held by people she already lived with and wasn’t passed around!)