Signs that your period is on its way are if you've grown underarm and pubic hair. Typically, you'll start your periods about two years after your breasts start growing and about a year after getting a white vaginal discharge. The average girl will get her first period around 12 years old, but it varies from person to person.
Here is a graphic of the muscles used in push ups. Compare it with the following about bench press. Both will give you a bigger chest and some more arm and shoulder size. Push ups work the stomach more. I've been working out in the gym for more than 40 years. My advice to anyone who will listen is to do a lot of push ups. Yes, I know the bench will get you stronger than push ups, but it is push ups that will allow you to bench when you get my age.
5022. Push ups are one of the most effective body weight exercises that you can do for your body. They provide excellent upper body conditioning by working all the major muscles in the arms, chest, back, and shoulders. Another area of your body that will feel the burn of push ups is your core, this is because you have to keep your body properly aligned during the movement, which is the job of your core. Along with increasing your metabolism and bone mass, push ups can burn a fair amount of calories.