As long as all has gone well, I agree with yakkityyak that you could go back after a couple of weeks. I gather that employed people cannot work the first two weeks after the birth)
It's pretty hard work, and support is the key.
I did some work, an hour here and there, pretty soon after DD1&2 (and I mean within the first two weeks, but just emails and phone calls from home), but both were sleeping through from 6 weeks. It made getting back at 8 weeks really easy, and people barely remembered that I had left.
I also attended a post grad course weekend (Fri-Sun) module at 4 weeks-brought hubby who handed me baby when she needed feeding, which I did discretely at the back of the class. I would have graduated a year after my class had I misssed it.
Breastfeeding was quite a juggle, but can be managed with pumps and reliable storage. I started giving bottles of expressed milk at 6 weeks, which was fine. Sometimes I had to pour it away, but I froze as much as I could as early as possible!
I really appreciated the adult contact when out, but then I am not a tiny baby person.
One note of warning-I had no end of unpleasant and insensitive comments from people who couldn't understand why I would do this, and were busy judging me.
This time around, I will take 8 weeks, and use annual leave to work part-time for the first month back. The first couple of months are hell anyway