Greyhound student discount?

I'm a student (just graduated from grade 9) and im taking the bus to my cabin, and im taking the greyhound bus. I bought the ticket with the student discount because im low on money lol, and the website said i needed some identification, so i thought i would bring my go-card (student id). the only problem is that i cant find my grade 9 student id, only my grade 7 one. is this okay to use, will they check the dates or anything? thankss :)