Pregnancy symptoms?? Maybe??

Hey ladies, so yesterday I was 6dpo and I felt like I had some cramping in the right side of my lower abdomen and felt bloated gassy and stuff, took a test and came back negative, now today at 7dpo I feel bloated, gassy, headache, really tired and i am currently feeling like I'm having twinges just underneath my belly button like tugging inside, weird feeling, and i felt nauseous all of a sudden this afternoon for no reason... could these be possible signs? Has any one else experienced any thing like this? Any advice would be great x