It can feel awkward to develop earlier than your friends but actually you are right on time. It is normal for girls to start puberty anytime between 8-13 years of age. Typically, girls will get their period between 9 and 15 with the average around 12 1/2 years old. Periods usually start about 2-3 years after they notice their breasts are growing. Some girls will get their period at about the same age as their mom but others don’t. It is possible that some of your friends have their period and breasts too but unless they told you, you wouldn’t know. You might want to ask your mom or other women in your family when they started to develop and if they experienced similar feelings. If it makes you feel uncomfortable to hear that you look older, let your friends and family know it bothers you.