Friend called me out before I was ready

I'm six weeks and two days and we are going for our first scan on 16th Dec, with a plan to do a 'big reveal' on Christmas Day to our family. For this reason, none of our families know, not even my Mum (as her reaction will be the best on Xmas!) It was my best friend's birthday this weekend, and she had a house party. I used the excuse of driving to not have a drink, which I thought I would get away with. However, one of my other friends cottoned on that I wasn't drinking (and to be fair it's pretty rare for me to not have a drink at a party!!) and she just wouldn't let it drop. She kept saying things like "you can have one, you know," and "do you have something you want to share with us?!" but not in a nice way, it was in quite an aggressive, confrontational way. Everyone else in our friendship group cottoned on what she was doing which resulted in the most awkward pregnancy reveal ever, especially as I think they could all sense that I just wasn't ready to announce it yet. It was like she was just doing it to prove she was right, not because she cared. I wasn't ready to spill the beans because it's my first baby, I'm still so early on, I haven't even had my first scan yet, and I didn't want to tell my friends before we told our family. I now feel like my Mum would be heartbroken to find out that quite a sizeable group of people knew before she did, which is making me second guess the Christmas idea that me and hubby were so excited to do. I'm so upset and angry with my friend for calling me out when I was blatantly not ready to, I really feel like she has stolen something from me. Am I justified to feel mad at her, and should I confront her about it?