If it's not super bad (like, can't wear underwear) it probably isn't a yeast infection. If you've changed soaps recently that could be it, if you're using scented toilet paper, or using bath salts/oils. Take showers rather than baths, clean yourself with a gentle non-scented soap, wear clean underwear.
It very well could be something like that. Maybe a soap you used or even the detergent to wash your clothes is aggrevating it!
Use a cold cloth on it, it'll help with the itch. You could have a bit of a pH imbalance.
A long time ago, I used to get really itchy before my period came. Not sure why but I always got it and after my period it was gone. Could be just hormones.