I got a negative home test but...?

I have mive cramping in my back along with the same kinds of cramping that usually accompany a period (which is way late and still a no show(as in if I had a positive test I'd be at about week 6)), I've been sick or queasy off and on the past week+, I get dizzy every time I stand up, my are sore and darker in color than usual, I've been running to the bathroom CONSTANTLY despite the fact that I haven't changed how much I drink, I've been getting headaches all the time, my sense of smell is really sensitive, I keep having these really crazy dreams (that can't be real but feel VERY real), my emotions are off the charts...... Either what else could it be (I talked to my Dr before I started my exercise and diet plan and it was all approved so I'm pretty sure it's not the 6 meal plan (3-5 being shakes with mix ins) or the amount of exercise... Or, what would cause a false negative on an early morning test?