Being on your period is a inconvenient and often downright frustrating time for most women, but imagine having no access to sanitary products and being unable to use most bathroom facilities.
That's the reality facing homeless women around the world today.
In London, women on the streets have to use bits of cloth to absorb blood or are "forced to go without", because homeless shelters are unable to provide adequate resources. Often these women are also reliant on snatching moments in public bathrooms to clean themselves, because there is nowhere else for them to go.
But three Londoners are determined to change things. Together Sarah Bakharty, Oliver Frost and Josie Shedden set up #TheHomelessPeriod, a change.org petition to pressurise the British government to address the issue.
"Shelters get an allowance from the government every year to buy items such as condoms, but still nothing for sanitary products," Bakharty told HuffPost UK Lifestyle.
"With funding for services so restricted most shelters or drop-in centres rely on public donations. If they don't have plentiful supplies (they more than likely don't as a box of tampons isn't something people tend to donate) then women will either have to be resourceful or go without."
In England, women make up 26% of those accessing homelessness services, according to Crisis Network. But putting an exact number on the number of homeless women is difficult because of 'hidden homelessness', which means those living out of sight in bed and breakfasts, squats, on the floors or sofas of friends and families or sleeping rough.
"We spoke to a number of shelters and it became apparent that many women have complex issues that have led to becoming homeless so it was important for us to talk to a woman who felt comfortable speaking openly about their experiences."
The trio, who work in advertising, were put in touch with Spires, a south London charity that helps hundreds of homeless and disadvantaged people - particularly women. They put Bakharty in touch with Patricia, a woman who used to be homeless. Patricia was able to share her experience of how she coped with her period each month.
“When I was homeless and I did have my periods, it was difficult, especially when you didn’t have any money to buy any sanitary towels, it was really difficult,” Patricia says. "I used to feel very depressed, it used to get me down. Why does a woman have to rip up a cloth to protect herself from bleeding?"
Bakharty adds: "Patricia would clean herself in public toilets. Cleanliness was just as important as resources, as it was a way of hiding her homelessness. If people knew she living on the streets then she would be putting herself in a vulnerable position. That was a very powerful thought and really stayed with us."
Research from Crisis Network echoes Patricia's story. They reveal that rough sleeping is extremely dangerous for homeless women, with many reporting being sexually assaulted or physically attacked. Like Patricia, these women protect themselves from harm by "remaining invisible".
The petition has really resonated with people, with 33,000 signatures and counting.
Writing on the change.org petition, Sascha Morgan-Evans wrote: "Every woman should have the right to access to essential items. Menstruation is not a choice. No woman should have to makeshift sanitary items."
Michaela Draisey said: "I believe all women should have the right to privacy and access to sanitary products when needed. Most people are not homeless by choice and to be able to provide something that could enable a homeless woman just an ounce of control, pride or even choice - it could make all the difference."
So if there is one thing members of the public can do to help?
"Take a minute to watch the film, share through social media and sign our petition. If people are inspired to do more, search out your local shelter and contact them to see how they can support," says Sarah.
To support #TheHomelessPeriod campaign sign their petition or donate (whether its money or sanitary products) by following this link