So my period started may 4 and ended the night of May 7th. And that's usually how long they last. It is now June 17th lately I've been not feeling well, acne is crazy bad, I cramp really bad, my lower abdomen is hard as a rock, and I thought I started today but didn't. I'm scared to take a pregnancy test because every time I take one when I think I am they always come back negative. Should I take one just to be sure or not?