What Causes Abdominal Pain, Headaches, Sickness And Pelvic Pain?

hello, my name is Jen, i have a few questions. im having multiple different symptoms and i don't know the cause. I have had hash abdominal pain on both the left and right side for some time, they are very sharp pains that may last minutes to only seconds. Also i have had a recurring headache. Followed by very dry mouth at night where it wakes me up to have to get a drink. Not often but sometime will i get a sharp pain in my pelvic area and once in a while during sexual intercourse with my boyfriend ill experience pain. Mostly in the morning ill feel very sick like i have to vomit but i wont, ill get very light headed and my stomach will ache. My last couple periods have been off, a couple days late but still they will come but not last as long. whats going on?