You need to have a serious conversation with your husband regarding how you feel and have him set boundaries with his brother so that he could relay the message to his wife. You shouldn’t have to be cleaning after grown people while they lounge off as if they’re in a spa. Honesty, I (as if it matters🤣) DO NOT CARE what you mind doing. YOU WILL NOT be cleaning after grown people while they SLEEP! Unless it’s your children and husband. Newly wed my ass! They’ve been playing house before they even became married 🙄. Regardless your husband needs to stand up for you. You’re not their slave! Pregnant or not!
Why are there grown people not contributing? If you're not bothered by the lack of help, and your husband works often, do you know what it is that you need exactly?
Why doesn't anyone else help with the chores? I would focus on tasks related to you, your husband, and baby. You shouldn't be required to take care of everything with no help.
You sound like you live in an Asian family I assume? Honest advice - move out and focus on yourself and your husband now. It’s not ok to take on the emotional burden of your in laws and it definitely does not get any easier with a child (my own personal experience). You can message me privately if you need more advice or someone to rant to