For 3 days I have been nauseated and I have had a bit of a head ache?

I have no idea why im feeling this way all of a sudden the only thing i can think of is that i had alcohol 3 days ago but not enough to make me puke but the next morning i felt a little sick.. i thought it would go away but it hasnt yet.. is this because im a lightweight? And also ive heard if your about to start your period and you drink alcohol before you can get sick. Is this true? Someone please help.