Dictionary HealthFemale Reproductive SystemAunt Flo Aunt Flo (AF) Published: September 30, 2017 What Does Aunt Flo (AF) Mean? Aunt Flo (AF) is another way to say menstrual period. The term was coined in reference to unwelcome family members who show up unexpectedly for a visit. In the fertility community, sometimes AF is positive as it can be required to initiate infertility treatment and other times AF starting is devastating as it means treatment has not been successful. FertilitySmarts Explains Aunt Flo (AF) The term Aunt Flo is used to refer to a menstrual period when someone does not want to overtly state that they have their period. This may be used in public situations when someone is feeling embarrassed about saying the word "period," or to appear casual. An example of a sentence using this term is: "I don't want to go swimming today because Aunt Flo is in town." Synonyms Aunt Flow Share This Term> Related Terms Last Menstrual Period Cycle Day Related Reading 14 Onesies that Celebrate IVF Babies IVF Pregnancy Announcements Fertility Podcasts Relatable Words After a Miscarriage Let’s Stop Arguing About Whether or Not Stress Causes Infertility Books About Infertility Tags Trying to Conceive Slang Menstrual Cycle Health Female Reproductive System Trending Articles Pregnancy IVF Pregnancy Announcements Egg Retrieval From Eggs to Blastocysts: Understanding IVF Attrition Cervical Mucus Identifying Stages of Cervical Mucus Artificial Insemination (AI) Implantation Calendar: What is Happening During the Two Week Wait?