I'm really worried, i feel quite bad?

See at school i did this test, it didn't mean a thing, but it was so hard and for once i just wanted to make my mum and dad proud. So i looked at the person next to me's test. Turns out i get fab marks and an A. I never thought it would amount to the much of a high grade and I only did it to make my mum and dad proud and give them something to be proud of me for. The test didn't mean anything at all and I know I wouldn't do it on a serious test. But I feel really, really guilty and I can't tell anyone because i'll get into MIVE trouble. I know i'll never do it again, what can i do?