horrid HORRID cramps and no period

I am not due for my period until sep 13th and for a long time now glow has been spot on with my period BUT last month I had two periods so it might be wrong about it. I am cramping so hard, shooting pain down my legs, I'm cramping so hard I'm shaking and seeing tunnel vision and then it passes and comes back. I'm having back cramps, I'm bloated and I feel like I'm dying. YET, no blood anywhere. There is a SLIGHT chance of pregnancy but I mean it would so early like even too early for implantation so I really don't think that could be it. I feel lightheaded and hot and dizzy and I just have no idea what's going on. Also no STDs of STIs. Only been with one sexual partner in the last 2 years. Do you think my period is just taking its glorious time to show up and that's what this means?