I said I didnt want a baby shower :/

My fiancés aunt sent a text message saying "I hope I can make it to your baby shower, I just invited myself"

I have told my fiancé, mil and best friend numerous times I didn't want one, this is my 5th baby, I don't have anyone that I really know( a total of 3 close friends) and I have severe social anxiety so I really wasn't happy when I saw this, I hate surprises. I didn't reply to her text, I'm not sure I should say anything to any of the 3 people who may have set this up, I'm not sure what is even set up, if anything, I feel bad because if they have gone behind my back to do this for me, it's not something that's going to make me happy even though realistically it should. I feel like knowing would make it a little better, so I could find a nice dress, do my makeup and mentally prepare, Im almost 37 weeks and feeling huge, cranky and unattractive, I don't want to be surprised or dragged into a room full of people I probably don't even know :/ How should I proceed? Help!