I only had a small tear that required a few stitches but I found that sex hurt for quite a while. We didn't successfully DTD until around 11-12w after birth and it continued to hurt a bit for some months after that although it did gradually get better with time (and lots of patience & lube!). I found that I had to focus on relaxing and trying to enjoy it or otherwise I'd tense up, anticipating the pain, and that would make it worse.