Ovarian cyst?

I have been cramping for six days now, I finally started three days ago, brown discharge spotting my first day and bright red (no clots) for two days, spotting. Not enough to fill a tampon I can wear a pad for 6 hrs and be fine now the bleeding comes and goes. I can’t sit still. I finally called my dr and ordered a blood test got a negative. My pain is crazy. It’s like constant cramps. It worse. It is mostly low pains, sometimes close to my ribs but always in my hip and pelvic area. I’ve been tested, nothing. I am not pregnant. The pain is now in my back. Every time I eat I have to lay down because I feel so sick. A friend of my asked if I ever herd anything about ectopic pregnancies? I need help pls. Is this severe enough for the er? Or could it be cramps due to an abnormal late period. Pls help