2 weeks pregnant symptoms?

I think I might be pregnant but I might just be late. Or it could be PMS, but I don't usually have these symptoms. I've been somewhat nauseous, i've had really bad dirrhea and i've bewn having headaches. I've also been cramping horribly in the pelvic area and my back has been hurting if I stand or bend over too much, which usually never happens. Even when i'm not on my period or PMSing. I'm just really worried. Please help.