3 neg tests - 8 days late - lower one sided abdominal pain. could i be preg?

Doesn't sound like: If you've had 3 negative pregnancy tests, i would consider another source for this pain you are having. Your bowels could be cause, could be musculoskeletal. See a doctor if you're worried about why you might be late, i.e. Cycle irregularity, but it doesn't seem as if it's about pregnancy. Can always take a blood test as well when you see the physician, but it doesn't seem as if you are pregnan.