brace yourself / her time of the month is coming
A Winter is Coming meme.
Winter Is Coming is Sean Bean as Ned Stark in HBO's Game of Thrones, delivering the words of House Stark. The full phrase - "Brace yourselves, winter is coming" - became a template for warning about anything predictable and inevitable: "Brace yourselves, the exam results are coming." It's the meme for seeing something annoying approaching and knowing there's no escape.