Would you be upset?

I'm 18 weeks pregnant and I have a group of friends there is 4 of us in total. We do everything together we have a group chat together that we are on every single day. One of them owns a salon and I just saw on snapchat that all 3 of them are at her salon! Now I wouldn't have gone anyways due to being pregnant and corona but they didnt know that. I'm just feeling so hurt that I wasnt even invited. Normally things like this are planned in the group chat even if one or more isnt going. I just feel like they went behind my back and planned to get together without inviting me. And this wasnt an accident they definitely planned it. I had no idea they were going. Would you be upset or am I just being hormonal? And if you think I'm right to be upset how would you handle the situation?