What is the reason for bleeding after cohabitation in a 42-year-old pregnant woman

Patient's question:

Sure, here is the translation of the content you provided:
No

Doctor's answer:

Hello! The return of menstruation after childbirth can be early or late. On average, it occurs once every three months. For some women, if menstruation occurs one month postpartum and they are breastfeeding, it may be delayed until a year later. This is also a normal phenomenon.