My period is about 10 days late and I have taken several hpt that have all said negative. My last period was June 1 and my husband and I tried to conceive that month. I have had some lower back pain and more discharge than normal but no blood whatsoever. I have also noticed some lower back pain lately. I stopped taking the pill in November and my cycles have been between 28-32 days every month. What is going on? Should I call the doctor and have a blood test?