I'm self employed, my husband took off 6 months. I went back about a day a week (but because self-employed I choose my own hours and it was totally flexible) from 3 weeks with my second (a bit longer with my first). That was technically using kit type days, for the few weeks, but the works the same. I then increased the hours slowly. I had c sections (my choice) but I recovered from them within about a week thankfully.
Because my husband was on paternity leave, it was absolutely fine. Tbh, it was a lot easier to work with a newborn than when they got older. Breastfeeding went fine, though it massively restricted what my husband could do with her in the day. Unless you've got a baby who refuses bottles from birth, like mine, I wouldn't personally recommend breastfeeding, certainly not exclusively, if you're juggling work in the early days. It meant he couldn't take her to baby groups or swimming, or meet up with other parents. He did baby massage, but only because I stayed in the car outside with my laptop!
Working whilst knackered sucks, but I was now knackered at the end of pregnancy than with my babies (terrible SPD causing insomnia), and my babies slept better as newborns than as older babies, so it was fine. From about 9m, when they were mobile, plus working more, plus my husband working again and sleep being worse, were far harder.