Nausea before period?

Emily

I have pcos and haven’t had a period for three years so I’m not sure what normal symptoms before you start a period are. I’m on combination hormone therapy to try and start ovulation and am now on my 7 day break where I should start my period. The last two days at about 8 o’clock at night I’ll feel extremely sick that literally lasts for about an hour but today since I have woken up I feel awful, almost like I have a hangover?