A question about my boobs?

They are a little tender and they have been for the most of this week. i haven't had my period yet for this month but it is late. but i chalk that up to leaving an all girls boarding school and coming home to my mom and my sister. also because i haven't gotten any in months. so I'm not sure if it's my period because they've been achy for so long and i usually don't get much pms. so other reasons my (small) breasts would be sore. also i'm only 16 so i'm still pubescent.