I was on depo injection that ran out 3 weeks ago, i didn't have periods while on this. then i had unprotected sex last week took ellaone about 32 hours afterwards and i'm now spotting does this mean i'm not pregnant ?

Maybe. Maybe not.: A urine pregnancy test done correctly will give a reliable result 3 weeks after sex (or when conception might have happened) or 1 week after missing a period. If done sooner, a positive result is likely real, but a negative result may be due to testing too soon, and therefore lead to a repeat test. Emergency contraceptive pills can alter the vaginal bleeding during the current and the next cycle.