It is narrated from Hazrat Sa'id bin al-Musayyib (may Allah have mercy on him) that he said: If a woman's menstruation stops and the reason is not known, then due to doubt she should wait for nine months; if pregnancy becomes apparent, then fine, otherwise she should wait for another three months, then she can marry.
Hadith Referenceسنن سعید بن منصور / كتاب الطلاق / 2483
Hadith Gradingمحدثین:إسناده صحيح مقطوع
Hadith Takhrij«إسناده صحيح مقطوع، «انفرد به المصنف من هذا الطريق»»