Hiya, your body will change after having children. It is very early days for you so give yourself time. ( months to get that big 9 months to get your body back. I was a size 6 before my first child and went to a size 14, I was horrified. I stayed at a 14 for a while then went to a 12. I then had my second child and went to a 16! I felt horrible, but it lasted only 3 months then I was back to a 14 again. Now after my third child I am a 10 to 12, my hips are wider and I would look terrible if I was a size 6 now. Yes I have a baby belly and could do with toning up a bit. But know with a little effort my body would be fine.
Please don't worry, 5 weeks is by no means a time to worry about your weight or body shape. You have done really well, and by the sounds of it you will get back to shape in no time.
Take care and congratulations