I usually get hot flashes a week before my period. i haven't seen my period this month yet and the hot flashes won't stop. what could be going on ?

Perimenopause: Although you are a few years younger than average onset, some women develop hot flushes in their late 30s due to hormonal fluctuations, which can also lead to anovulatory cycles - missed periods. See your clinician about trying hormonal contraception - pills / ring to reduce vasomotor symptoms (hot flushes) while also regulating ur periods and preventing unintended pregnancy.