Let's be honest, everything's worse in winter. It gets dark at 4pm, it's freezing and Dry January is in full swing.
And to top it all off, our periods seem to be 100x worse.
Yep, you're not going mad. if you feel like your time of the month is a little more unpredictable at this time of year, there's actually a scientific reason behind it.
It's thought that sunshine helps the body increase its follicle stimulating hormone, which aims to regulate the reproductive processes of the body. So in winter, you ovulate less frequently and experience a longer menstrual cycle compared to the summer.
It's good news if you're looking to conceive - a recent study from the Journal of Obstetrics and Gynecology found that sperm quality often deteriorates during the summer, as it doesn’t function as well in heat.
This is coupled with the discovery that the amount of daylight impacts your eggs, due to the variation in quality of the ovum or endometrial receptivity.
However, if you're not ready to start a family just yet, it's just a bit of a pain in the ass. And we're sorry to tell you this, but it can also make your PMS that bit worse.
Dr Preethi Daniel - Clinical Director at London Doctors Clinic - tells Metro: ‘As the days are shorter and darker, your mood can be adversely affected and add to that the monthly rollercoaster of hormones that arrive with your period and it can all seem even bleaker.
'Sunshine helps us make vitamin D and dopamine, both of which boost mood, pleasure, motivation and concentration.
‘Furthermore, winter means we spend more time indoors and we move less and eat more. This can have a bad effect on premenstrual symptoms as it has been found that women who are more active had much more regular and manageable cycles than those that hardly worked out.'
We think this is a great excuse to buy a jumbo box of chocolates, don't you?