Im on depo been on it for half a year to nine months but ive spotted and its never really happened…

Im on depo been on it for half a year to nine months but ive spotted and its never really happened before my next shot is on the tenth i had sex unprotected 3 times this month i dont feel pregnant at all no sensitivity in the breast no frequent urining no cravings or cramping or sensitivity to certain smells my original appt was canceled and is now moved so i have a short window to get my next shot. I do plan to get a pregnancy test to be sure this stuff is still working but is it worth even checking?