I waited about 6 weeks. I don't remember any burning sensation, just a sense of something being used again after a while . Burning sounds horrible though, hope someone who knows more will be a long soon.
Yes - it burnt like crazy and that was 5 weeks after. BUT it did turn out to be an infection. GP said that an infection 'up there' is common after a CS but didn't say why! Maybe get a swab done just to make sure. I certainly had no symptons at all - apart from the really bad burning pain during sex. HTH