Could I be pregnant?

I have been getting headaches, feeling nauseous, getting dizzy, craving foods I hate.. Then I had an ovarian cyst rupture and was in the ER. With all my other symptoms they did a pregnancy test with a urine sample and it came back negative. Now I have my period a week early (it's never this early) and it's been on and off and a little lighter than usual. Could it be implantation bleeding? Idk what to think and if I should even test or wait and go to an obgyn or something? Any advice?