Is it time to bust stigma with a period emoji?

There are emojis for almost everything - a ginger cat blowing a kiss, the Queen's Guard in traditional costume, even a floppy disc - but there are no emojis for one experience central to human existence.

Every month for a large portion of their lives, roughly half the population discharge the lining of their uterus. It can cause painful cramps, lead to tiredness, irritability and mood changes. Sometimes women want to vent about it, but there are no emojis to help them do that.

One international NGO wants to change that. Plan International is calling on Unicode to release an official 'period emoji' to help combat stigma and normalise periods.

The charity is asking people to vote on their favourite period emoji and will send the winning design to Unicode Consortium - the organisation that makes decisions around computer software text and characters, including emojis.

In the United Kingdom, a poll run by the charity found 64 percent of women would feel uncomfortable discussing their period with a male friend.

Plan International wants to make conversations about periods more comfortable.

"Periods can be unpleasant and painful but they're nothing to be ashamed of. In fact, they're a big part of our lives," the charity said in a statement on its website.

"It's time the conversation was made easier. Half of women aged 18-34 would find it easier to talk to their partner about their period if there was a period emoji - that's why we're calling for a #periodemoji to be made available on keyboards worldwide."

The designs include a diagram of a the female reproductive system, a sanitary towel, a pair of period undies, a calendar with blood droplets or a personified droplet of blood, with three emotions - happy, sad or pain.

The charity works to advance the rights of children and campaigns for equality for girls. It says stigma around periods means girls are missing out on school and women feel ashamed and uncomfortable talking about their periods. The charity says one in 10 girls in Africa miss school when they have their period.

It's not just an issue in the developing world. In New Zealand, the Salvation Army campaigned for donations of sanitary items for low-income teens and women. Spokesperson Pam Waugh told Newshub some young girls are using newspapers and telephone books instead of tampons and pads.

It's worth noting not all women get periods, and not all people who get periods are women. And while we wait for Unicode to make a call, we'll just have to be creative about how we discuss the biological function.