Nausea, stomach pain, headaches and pain all over?

On Sunday I was getting severe headaches and some stomach pain here and there. I took some ibuprofen and normally it works everytime but this time it didn't. I got plenty of sleep the night before so I know it wasn't from that. Although I am very late on my period. It's not a big change because normal girls can keep track as it usually falls around the same day but with mine sometimes its the fourth day next time it's on the twentieth, you never know it changes everytime. So this month it should've been the first or second week and now it's almost the last day. School has been stressing me out a little but not that much so I'm not sure why its so late and I'm deffinently not pregnant. Anyways so the next day on Monday I was taking a shower then all of the sudden I felt like I was going to throw up. Everything was just like effecting me and I couldn't take it. I had to sit out for a few minutes before I could regain the ability to go back in. With what I was feeling I was nearly crying. After that I continued getting ready for school but I still felt nauseated and had stomach/head ache pains. I stayed home from school and took a nice long nap. When I woke up I felt fine but after lunch it all came back except this time I started getting pain up my left arm. I took ibuprofen and for dinner I only had a bagel because food still nauseated me. I haven't thrown up only baby barfed a few times. By 8 I had pain up my left arm/leg, my knee hurt, my back hurt, had the same headache pains and my elbow hurt. I had a baseball game but I didn't go due to my condition. By the time I went to bed I had pain all over my body and now I'm laying in bed not being able to sleep and still have the stomach pains, nauseation and pain everywhere. What could this be? Never happened to me before although when I get my period I sometimes get bad cramps yet it still hasn't arrived. Sorry this is so long but thanks if you read it all i just wanted to include detail for a good possible answer.