From: Rabbi Moshe Sofer
To: Rabbi Yaakov Koppel
A nursing woman with no current veses experienced pain and saw blood on three occasions during intercourse, with a physician and her mother attesting to a wound from childbirth. The Chasam Sofer rules she cannot be fully permitted without examination due to her established pattern of sensing moisture mid-act, but permits her to her current husband using a cloth pouch method that can confirm the blood originates from a lateral wound rather than the uterus.
Source: Shu"t Chasam Sofer YD §153