Worried to go to the doctor or not?

I’ve been feeling off since yesterday like cramping on the left side back pain last night on my way home from work I got super light headed everything was moving while I was driving felt like I was going to pass out luckily I was coming to a stop sign say there till I was ok to make it home. I keep thinking it’s my period but nothing’s there whenever I go to the bathroom but period isn’t due till next Tuesday. Me and my SO have not been trying to conceive but if it happens it happens I have taken two pregnancy test and they are negative. I had made a post recently about me being extremely late this month for my period and didn’t realize it like three weeks late. I do not know what to do.