What Causes Dizziness Prior To Menstruation?

hi am feeling dizzy since 3 days, when i wakeup early in morning. i went to BP chekup, but evrything is normal. this is happening since 3 dys. my periods are yet to come on feb 4th or 5th. in another 4 days i mean. it never happend to me before . can u help me why am i feeling like this?