Why huKUcheza? And not Humecheza? Is this another rule i dont know yet?
Maybe, it is a bit difficult for us to know which rules you know :)
Anyway, here are the infixes for the different past tenses
Umecheza: You have played
Hujacheza: You have not played
Ulicheza: You played
Hukucheza: You didn't play
to add to Ernst's comment, the tense infix '-me-' is always in the affirmative, and it shows present perfect tense. It's negative counterpart is '-ja-'