hi i am olive im 13 and i have been have constant headaches for a week now about around the same time 7:00 pm and side cramps and under my stomach has started to tighten as if it were been twisted when i go poo also Ive have been getting very frustrated and angry and hot  mostly all day and my last period was very horrible which was in november the 29th  and ever since then i havent been feeling 100% i have been taking nyquil but it only works for an hour and im not sexually active at all never have been can i get some advice please on if it is serious