What are the odds? I Need help!!

So my husband and I moved from CT to NC a little over 2 years ago. My mother in law and sister in law are coming Down for xmas this year! We decided we were going to tell everyone I was pregnant on Xmas because I wouldn’t be able to hide it from my mother in law (we are drinking partners lol). So to be fair, my mom and everyone else will know the same day over FaceTime! Soooo..... my husband just calls me and tells me his brother is going to propose to his girlfriend xmas eve or Xmas (he’s not sure yet)! I’m so happy for them of course but what Are the odds? Idk what to do now ? Should We wait and I try to hide being pregnant for a week (she is staying til New Years) even though is going to be torture and stressful trying to hide it or just go ahead with the plans because it was already our plan?? I don’t want his GF to think we are trying to out shine them because I’m doing it 2 weeks earlier than we are “suppose “ to! But I loved the Xmas idea of surprising everyone ! Also we are surprising our son xmas eve with a “ I’m going to be a big brother shirt “ on Xmas eve (he’s 9 1/2 and doesn’t know yet). What y’all think ??