Please give your advice and help i need it very worried:(.?

i am sixteen years old, i last had PROTECTED SEX in october, i missed my period in october had it in november, missed it in december - took a pregnancy test to see and it was negative, anyway missed it again in january - took another one it was negative, went to the doctors and they said it was negative. had it in febuary, and march and now missed it in april may and june, but on the 1st july i wiped and had brown discharge? and i wiped alot and there was blood alot of blood, but it stopped today the 3rd, i am worried cause it wasnt like a normal period? i don't really want to go the doctors i just want to know from other people is it normal to be like this?