It was narrated from Anas: that the Messenger of Allah said: “Three days for a previously-married woman and seven days for a virgin.”
It was narrated from Al-Harith from his father that when when the Messenger of Allah (ﷺ) married Umm Salamah, he stayed with her for three days, then he said: “You are not insignificant in your husband's eyes. If you wish, I will stay with you for seven days, but then I will stay with my other wives for seven days too.”