What ya'll think please answer?

I just got to thinkin about my 3yr old colt ( btw im gettin him cut next month when my farrier can do it) ive owned him for a yr now and when i got him last april i was told he was 3 and he wasnt he was just turnin 2 and he had already been ridden for 60 or 90 days she walked,troted and cantered him so when i got him i rode him once and turned him out til last fall then started riding him lightly but ive noticed that when i ride him around the yard his back legs crack the whole time could it be from being ridden so much at a young age? Im goin to get my vet to check him out in the next 2 weeks should i stop riding him ? I dont wanna mess him up he has very flat feet and when i got him he was walkin on his heels but now their gettin better.. Please no rude answers i just want ya'll thought on this.