I assume the two months was how long it was for Clark before he is sixteen (eighteen?) and eligible to withdraw for high school early. For all we know he's been a model student and that would allow him to take college courses early.

CLARK: No. I'm just worried I'm a jinx.
JONATHAN: A jinx?
CLARK: Yeah. Let's face it, ever since she's known me, Lois's been kidnapped, frozen, pushed off buildings, almost stabbed, poisoned, buried alive and who knows what else, and it's all because of me.
-"Contact" (You're not her jinx, you're her blessing.)