Bleeding is the real big sign for miscarrying, it may just be pregnancy symptoms. Backaches are a big pregnancy symptom. Not all symptoms stay around the whole pregnancy, so your breast tenderness fading may simply be a passing of a stage into another. If you're truly worried, call your doctor. He may want to do an ultrasound or HCG test to make sure your levels are still rising. Good luck, but I wouldn't worry yet if there's no blood.