MIL and SIL hang out with husbands ex

My sister in law and mother in law posted on Snapchat that they were at a haunted house with my husbands ex girlfriend.

I didn’t receive an invite... although I am 37 weeks pregnant. It’s really making me feel terrible that they are all hanging out. 😢

Their break up was really bad and my MIL was upset that they broke up and did things like saved old relationship gifts/pictures my husband had tried to throw out. Towards the end of their relationship when things started to crumble- She bought his ex presents (expensive jewelry) and gave them to her and would say they were from him.

I was friends with my husband (and a friendly acquaintance with his then girlfriend) long before we started dating. I feel like my MIL resented me thinking I was the reason they broke up.

She was never fond of me since me and hubby started dating soon after they broke up. As time passed and we eventually got married her attitude towards me started to change- even more so when we found out we were pregnant. She’s seemingly very excited and happy for us.

Should I say anything to my husband or just keep quiet?

I just feel really sad as I’m always trying to do anything and everything to feel accepted by my MIL but this feels like a slap in the face...