Suggest Treatment For Dizziness And Migraine After Off BC Pill

hi, i came off cerazette just over a week ago. i had sex on the saturday and took last pill on the sunday. since coming off it, i feel extremely bloated, dizzy and light headed, back ache, belly ache and migrane! have take two pregnancy tests as my stomache is huge compared to normal but both have been negative. also have not been to the toilet properly for about 3 days.

do you know why this is?