Can you tell me if I am overreacting?

So I am 37wks pregnant with my 3rd child and my mother in law offer to throw me a baby-shower. I did not want to have one, but I said okay anyways. So she put it together and it's tomorrow. Well today she calls my husband and ask who is coming over to clean up. (mind you at 4pm, my husbands at work and we live over an hr away). Im like, why did she wait last minute? and who asks the guest of honor to clean up for the shower you are throwing them? Anyhow, that's not the biggest deal, so today she sends out "last minute" fb invitations and sends one to me. Guess who she invites, my husbands ex girlfriend - and the ex is attending. This makes me uncomfortable. Maybe I'm hormonal and insecure because I feel fat and unattractive. I have always sensed that she doesn't think I'm good enough for her son, this kind of makes my thoughts seem validated. Am I overreacting?