Dealin w/ an unexpected period?

I'm at my grandma's and my period just came on unexpectedly. I went to bed like 2 hours ago, and woke up about 10 minutes ago to go to the bathroom. It went through my panties, my pj pants and onto the sheets a little bit. I have pads and tampons with me because I always keep a bunch in my overnight bag, just in case. I don't however have any pain meds, and my tummy and back REALLY hurt. My grandma is up reading. I've already changed out of my bloodied clothes. I don't want them to stain, and I really need some medicine and a heating pad. I am sosososo embarred right now. what do I tell my Grandma? I need her to help me get the blood out and need some medicine, but don't know how to ask. We've never talked about periods or anything before even though we're pretty close