Umm Salamah narrated:
"While I was lying down with the Messenger of Allah (ﷺ) under a blanket, my period came, so I slipped away and put on the clothes I used to wear when I was menstruating. The Messenger of Allah (ﷺ) said: 'Are you menstruating?' I said: 'Yes.' Then he called me and I lied down with him under the blanket." (ES)
English reference (ES): Vol. 1, Book 1, Hadith 284 (ES)
Arabic reference (ES): Book 1, Hadith 285 (ES)