AITA for having my fiancee return my ring after she planned a "surprise" reveal of her pregnancy at our engagement party?

I proposed to my fiancee "Allison" (27F) about a month ago. We decided to hold off on actually getting married for about a year or so and just have the engagement party this year. The party was being held at her parents house. It was my grandparents ring and I want it to be passed down eventually.<br><br>The party was going great up until her best friend got up to give her speech. She actually ended up announcing Allison's pregnancy instead which was met with a lot of applause and cheers. I was not expecting this at all. I was actually mad, not because she was pregnant, I was mad because she went behind my back and decided to use this opportunity to make this announcement. <br><br>The attention immediately got diverted from our engagement and the rest of the party was people congratulating her on her pregnancy. I didn't get to do any of the things I wanted to with my parents at the party or anything like that. I also felt that it made our engagement look kind of secondary which was disappointing for me seeing as my family are very big on preserving family heirlooms and passing them down. <br><br>I basically IGNORED Allison for the rest of the party and only played the role of a loving and supportive fiancee to everyone else. After the party we got into a huge argument in the car. I told her that what she did was absolutely disrespectful towards our engagement as a whole and especially disrespectful towards my family/our future children. She started crying and saying she did it because she wanted to make things "special" and that my reaction was making her question whether or not she even wants to marry me. I want her to return the ring for now until she apologizes. AITA?