Aquasea, consider this, you may or may not have an easy birth. You may be in physical discomfort 4 weeks after the birth particularly if you go overdue. If you are like 99.9% of new mums, you'll probably be really really tired, stressed out, worried about a zillion things, ecstatically happy about your new little bundle of love, and your hormones will still be raging all over the place and you may or may not still be struggling with breastfeeding (if you choose to do so).
My mil arrived for the weekend, 3 weeks after our gorgeous baby boy was born. After cooing over him for a while we started chatting about the birth. I had a very distressing 2 weeks going overdue and a very painful inducement. I had internal stitches and felt like I was peeing razorblades for a few weeks after giving birth. It was also a very stressful time - as a new mum I was exhausted, nervous that i was doing everything wrong and just plain full of moments of exhaustion and elation at having my baby as well as still being really sore down below! Instead of sympathising about the difficult birth, my mil's exact words were "Oh well, never mind,there are a lot of women who've had it a lot worse than you dear. At least you didn't have a c-section." She then continued cooing over baby boy. I wanted to scream at her and shake her and tell her to get out of my house! I'm sure to this day, 9 months on, she has no idea how much those words upset me. Even now, everytime she visits, I get parenting tips and comments on my inability to express a full 8oz of breastmilk right through to the food I give to baby and to the safety of his toys!!! Get the picture?
So, my suggestion is this - compromise and let them come over, but under NO circumstances should they stay in your house. You say you live in a 2 bed house, well put it to them this way, do they really want to be woken up at least 3 times a night by a screaming baby? Get your hubby to research reasonable hotels/guest houses and be firm about this. Honestly, you may end up seriously damaging your relationship with them forever if you don't set boundaries and give in and then end up resenting it forever. This time is about you, hubby and baby bonding and I think family shoudl be sensitive to that and put your needs first. I think it's nice that tehy want to visit, but you will live to regret it if you let them stay. Just think about how anxious it makes you feel NOW - then imagine how you will feel when they are actually here, in your house, trying to 'help' but pissing you off! Good luck!