Hello You didn t mention the duration of stomach cramps ,however sometimes morning after pills also causes nausea and stomach cramps . But in your case hyperacidity may be the reason of stomach cramps particularly in the night . Tension , hectic hurried life , fatty food , junk , red chillis are the few items whic causes stomach cramps . So try to avoid these things . I usually prescribe proton pump inhibitors like pantoloc forte , twice in day . You may need antacid syrup ( good if it contains oxetacaine ) . Good luck.