Women are phoning Donald Trump to report their periods.

The phone lines at Donald Trump’s campaign headquarters are clogging up with women calling in to report their periods.

‘Why?’, you ask. Well, it’s all to do with who the presumptive Republican nominee has chosen as his running mate in the US presidential election: Indiana Governor Mike Pence.

Earlier this year, Pence passed a law that required miscarried or aborted fetuses to be buried or cremated, inspiring a protest campaign called Periods for Pence.

As the campaign’s anonymous founder wrote at the time:

“Fertilized eggs can be expelled during a woman’s period without a woman even knowing that she might have had the potential blastocyst in her. Therefore, any period could potentially be a miscarriage without knowledge… Just to cover our bases, perhaps we should make sure to contact Governor Pence’s office to report our periods. We wouldn’t want him thinking that THOUSANDS OF HOOSIER WOMEN A DAY are trying to hide anything, would we?”

Hundreds of Indiana women embraced the cause, phoning, emailing and tweeting Pence to inform him about their monthly flow.

And now, with Trump’s announcement, the push has gone national.

Followers of the Periods for Pence Facebook page have been dialling Trump HQ and reporting back on their progress.

One asked where to send her used tampons for examination. Another questioned whether she needed to obtain proof of her menopause.

The Periods for Pence founder is even collaborating on complementary movement called "Tampons For Trump", which is also fast gaining traction on social media.

Pence's appointment to the Trump ticket is hardly a surprise given the presumptive Republican nominee's attitude to women's health and reproductive matters.

Earlier this year, Trump famously called for women who seek abortions "face some form of punishment", a comment which he later retracted after immense public backlash.

And who could forget the time he said journalist Megyn Kelly must have had “blood coming out of her wherever” when she grilled him during a campaign debate.

Might be time to check your voicemail, Mr Trump.

Video via CNN