Whats wrong with me ?

coupl of days ageo i had bad headache and sicked out yellow sick then the next day i couldnt go for poo abd bad cramps and bloating then i srted shittin all the time it was coming bk yellow thought a may be pregnant but started my period now its back t cant poo and bloating and cramping again and also i came on ma peiod sunday night theres blood thee when i wipe but noon on the pad only lil bits its no tuesday moring i thought i would be heaver then that whats going on