Really bad period cramp!!?

Well I have never had my period but I'm developed enough to have it and I'm 13. About 3 weeks ago I spotted for 5 days. Then 6 days ago I started spotting again for 5 more days. I had minor cramps and barely any spotting either time but I had blood specks this size: "-" and 2 on the fourth day of spotting that were this size: "O". Then I had no spotting today. However, I had a pretty painful cramp near my right hip that was bugging me for a few hours in school. I still had no spotting though Orr period. Since I was just spotting and then I had that big cramp, should I get a period soon? When should I get it? This week? Next week? Next month? I know it's impossible to tell me exactly, but can you just give it your best guess? Thanks!