(noun) + the week of the female period slang. orig in university campuses,with reference to annual charity 'rag' week, mainly used to describe male frustration at girlfreinds period i.e. 'been getting it regular with your bird eh, john' 'nah mate she's on rag week'
RAG WEEK
Meaning of RAG WEEK in English
Slang English vocab. Английский сленговый словарь. 2012