What is required of one who, after performing Umrah and delaying the release from ihram out of forgetfulness, had intercourse with his wife, cut his nails, and shaved his hair?

If you have intercourse with your wife during Umrah after Sa'i and before shaving (or cutting hair), your Umrah is valid, but a sheep is obligatory upon you, because intercourse before shaving does not invalidate Umrah, as stated in Al-Mudawwanah and Al-Mughni.