Pleaseee HELP ME IM 16 N I Think Im Pregnant!!!! please help?

ok so usaly i get my period on the 4 some later some times earlyer cause i guess im young, but i missed it this mont, now it is the16 n im having very nausa but no vomiting, n my periode is brown im not even sure it is my periode no sighns, n i have been having unprotected , could i bee pregnat i dont know what this brown discharg is, please help