I been throwing up for 2 weeks and had spotting and cramping but no period my side hurt and headaches took a test its negative what else could it be?

Ectopic pregnancy?: Description of your symptoms make me think about long list of potential conditions. Some of them are really urgent and may become life treatening if not taken care of timely. Urine pregnancy test is non diagnostic if you have ectopic pregnancy (outside of the uterus). You need bloobwork, ultrasound or ctscan, and most of all good clinical exam. See your doctor to sort it out.