I just got my 1st period on July 11. I went on this website www.Beinggirl.com and I went on their Period Predictor thingy and it said I will get my second period on my BIRTHDAY!!! August 7th But they asked what my cycle was and I guessed 28 days because that's the number they had already put. So what's a cycle because I really want to know and me and my family are planing to go to Hershey Park for my B-Day and I can't go there when I'm on my period and my period was really heavy the first day I got it. I'm only 11 and I really need help with this. I'm to embarrassed to ask my mom these things.