i was playing halo reach like normal i played 3 games of campaign doing custom challenges when i noticed my credits didnt increase at all i knew i wasnt credit capped because the game would still have a total amount of credits earned instead of giving me 0. i tried shuting down my xbox but it sill didnt give me my credits. the only credits i got were from the daily challenges that waypoint makes.
Track your credits at HaloTracker. Best way to know how many cr you get day to day.