We can probably all admit to crying our little hearts out after sex once or twice, right? That's because post-coital dysphoria, known as the post-sex blues, is WAY more common than you think, ladies. 

Around 150 AD, a prominent Greek physician called Galen wrote: "Every animal is sad after coitus except the human female and the rooster." But we think Galen might have been a bit off the mark. 

The Journal of Sexual Medicine reported this week that 46 per cent of female university students admit to having PCD at least once in their lifetime. And another five per cent of the 230 tested said they experienced crying after sex "a few times" in the last month. Ah, we feel ya sisters.

Various other studies have shown that 10 per cent of women experience the post-sex blues after intercourse and they describe the characteristics as tearful, anxious, agitated, feeling depressed or feeling aggressive. But sometimes we feel all these at once, right?

In another Australian study published in the International Journal of Sexual Health in 2011, a third of women revealed that they feel sad even after good sex. Now, this is can be when we start to think what the hell is wrong with us? but you're not alone. 

The Queensland Institute of Technology have studied the effects and say that hormonal shifts occur after orgasm, which can trigger post-coital headaches and therefore, they can be to blame for your feelings going downhill. Damn hormones!

The lead researcher, Dr Robert Schweitzer, from QIT said that the findings come from "investigating the correlates of sexual functioning in women.

"The results of our original research in this area have now been confirmed in an international, multinational study on negative post-coital emotions, which appear to have evolutionary functions," he added. 

See ladies, you're not as strange as you think. So if you start to shed a few tears after sex (even good sex), don't worry too much because you're certainly not alone.