Please answer I'm really worried!?

I'm not ually active. I am a virgin. I my period is 15 days late. My period is usually off by a day or 2 but it has never been later than a week. I'm getting scared because yesterday I started sweating when it wasn't hot. I got dizzy, and I have been really nauseous but I have never thrown up. I am 16, so it can't be menopause. I'm afraid to tell my mom because she will think im pregnant. I have been getting my spine readjusted could that have something to do with it in any way? It's not like it's one of my first periods either, because my first 3 or 4 periods were about a couple of months apart. I got my first period a month after I turned 13. Please answer I'm worried.