Thanks for all the replies. My relatives will be here for the whole month and I'm due in the first week so if all goes to plan they'll be here for the first three weeks after bub is born.
Unfortunately I definitely won't have my Mum or Dad on board. When I had my DD my parents and in laws practically squatted at my house, they were helpful but it was also very overwhelming. I appreciated the help but they were also intrusive in that they'd just take DD and wouldn't want to give her back, and I didn't have the space to establish breastfeeding which I had huge problems with and eventually gave up and bottle fed.
I was hoping that this second time, which will probably also be my last baby, I could do things differently and have more space and time. Now with extra relatives here I know it's going to be difficult. My parents would have been offended in the first place when I told them to back off this time, now they will be extra offended because in their world the worst thing you can ever do is offend people and especially overseas guests, their comfort should come first.
I just know it's going to be stressful which is why I'm worrying about it from now.
I appreciate the replies though, I'm going to try to take some of the advice and toughen up and just focus on what's best for me and DH and our children. I just know I'm going to end up offending people. I really wish they would come later, like a few months after I've had the baby when I've gotten used to having a newborn and toddler; they think they're doing something so great for me to come when I'm due to give birth but I'm a private and anxious person and I really don't see it that way.