Ellipsisters 

When multiple persons synchronize their periods, resulting in three simultaneous periods (like an ellipsis).

Jamie: "What's wrong, Charli? Is it your time of the month too?"
Charli: "Yeah sorry, cramps are absolutely destroying me right now."
Riley: "No way, mine just began this morning!"
All: "...ellipsisters! (cheering then groaning)"

Ellipsisters by Stikki Thiccums January 1, 2024