Why do I get itchy on my period?

You should ask a doctor on that. Hopefully they know a lot more on this than we do. Good luck!!

More hormones racing around, probably. I’m the same way.

It is because your body temperature peaks around that time, so you are hotter and sweaty there (and everywhere), so you will itch a bit more- underwear is not the loosest fabric so the sweat can make your skin feel itchy. If you use sanitary towels it would likely be worse as well, as they could irritate the skin slightly and mean it itches even more, as well as being another layer to make you warmer there. It is perfcetly normal :)

If you itch still once your period has ended then it is worth seeing a doctor in case you have a simple infection like thrush, which an easily be sorted with treatment.

Yeast grows in warm wet environments.