panicking

So I am 5 days early to my period , which is abnormal for me . So I feel a bit lightheaded and dry mouth which  is due to the stress I believe. I supposedly ovulated on the 21st and I am on 30 day cycle . I had sex on the 24 it was protected but I am so  skeptical. I am have cramps but no tender breast which I always have during my period . Should I still take a pregnancy test or could this be implantation bleeding ? The period seems a bit watery