My first period happened on the one day that I couldn’t wear underpants so that was great. The first time I went to the toilet that day was at the end of the day. I was like “um why is there brown crap on my pants.” Then I figured it was my period. So, I was walking around the whole day with brown crap on my pants, with no idea, and everybody could see it. Amazing.
Also you can say period here if that’s the reason you’re saying “.”. Period.
You get periods based off genetics. Skinnier people tend to get periods later and if they are anorexic, then it can be dangerous because they don't have a lot of blood to waste. Overweight people and average people get them around the same time. Also Petaya, ma'am, too much info.