Anyway all these tests are wrong?!?!

J
Been TTC for 2 years with my SO. Got my highest ovulation on the 3rd and I went to ER yesterday with back pain and lower abdominal middle left side pain. Had an ultrasound done said I have a cyst on my left ovary and a kidney stone in my left kidney. They also did a urine and blood test to see if I was pregnant and all negative but I would only be like a week preg. if I was.
 
So my question is can I be pregnant even tho all of these are negative? 
Btw my AF is due on the 18th.
Baby dust to all!!!