We've done the same thing and it's never a nice conversation but our midwives adviced it and said we would want time to ourselves - we completely agreed and although it's never received with happiness your parents/in laws will completely understand! The only thing I would say is you stick to what you say, if they come back pressuring, don't cave as you've decided between you and your partner what you want and that should be final! The only thing we've said is that if there are any complications with me or baby and we need more support then there is the possibility it would be less than a week by ourselves but it all depends on what happens. You both need to do what's best for you and you'll never get this quality time again just to get settled and figure out your new routine without anyone's opinions ❤️
I knew I would have an issue with parents/in laws understanding the boundaries we wanted to set so I made a group chat for updates (I still haven’t gone into labour and they were all asking all the time) and I politely put in some ‘rules’ so they all got the same message at the same time and one of those ‘rules’ was no unexpected visitors at the hospital/home so we had time to bond with baby and also recover from the birth. It worked really well I would definitely recommend!
Honestly, just tell them. My husband is going to be telling our families. We need to settle in with the little one and adapt to new life, and so does the baby. Sometimes honesty is the best way forward xx