Once a month nausea please help! ?!

Roughly once a month I will get this weird sickness that has odd symptoms I'm male and 14 years old and live a healthy active life. It will start off with my periferial vision being blurry for roughly 30-40 mins the stops. Then imeadiatly after, I get a headache that is strong for about 20-30 mins then gets better but still stays. Then my friend will notice I'm turning pale or green in the face and I will then proceed to be nausish and feel very sick then eventually throw up. Any way I just want to know why this is happening to me? Is it more serious than I think? Please help.

Thanks ,
James