Look...friend..Sometimes I don't always buy the idea of simple logical reasoning to be on a safer side when taking a decision. You need not to ask anyone here..I am sure this is very important to you. Since you know your test comes up 5th, then go there as early as 7 AM...Wait around and study the situation of things around. State your case and you probably might have the chance to even write before those scheduled for 10, 12 pm....