Please teachers help!!!!! Period!!!!!!!!!!!!!!!!?

Omg im so freaked out!!!!!!!!!!!!
Im 15 and am in grade nine first year of high school here in Ontario!!
Anyways i was at school today and im kinda failing science so i went to see one of the guidance counsillors Mr. Whitlock at my school! Cause he is helping me try to pass!
Anyways i was in there for about 45mins and when i went to stand up there was blood all over the chair i was sitting in, in his office!!!!! I was like **** under my breath and sat now quick!!
And he said everything okay??
And i said no!!!
And he said whats wrong?
And i said um i hope your not mad at me but i kinda started my period and its all over the chair and my capris!! (they were white!!!)
He said Oh and gave me his sweater and told me to go to my locker and get my gym shorts and asked me if i had any pads or tampons and i said no cause i wasnt expecting my period!
and then he said okay i will go get you one from the office!!
So i put my gym shorts on and went back to student services and he gave me a tampon

i gave him back his sweater which was white and said sorry and he said no problem dont worry about it!!
Omg im so freaked out! I have to go back to see him tomorrow about science and im really embarrassed about it!!!
(he is pretty young like in his late 20)
so what do i do??????????
thanks!
Jenna

Oh, honey, I totally understand you being embarrassed, but what could you do? Probably every woman out there's gotten a period when she didn't expect it and wasn't prepared for it. He was really cool about it today (I mean, he, a guy, went and got you a tampon - that's cool), so you just have to let it go and act like it didn't happen. I mean, it's not like you actually want to discuss it any more, right? He'll understand that you're embarrassed. You can't change what happened, so my advice is to just try and let go of it. (And always have some supplies in your locker from now on!) Poor thing!