HELP IM A GIIRL AND II THIINK IIM GAY ?!?!?!?

kaay iim a 17 year old giirl never really been wit fellas lOl...asin ii had mii firlsr snog at 16 ....im an attractive girl small...petite size 6 long brunette hair hazel/ green eyes...boys have ALWAYS been after me bt i think im more attracted to girls...iv come out ta friends that im bi but ii wud defo pick most girls over boys...ii have a boyfriend and ii love him...but if we ever finished then ii wud prob go for girls??.....we havent had yet...but ii think we defo shud do it to see if iim completely gay..its wrecken mii head....id NEVER say this to any of mii family members i no i shouldnt b ashamed but ii am :( ii dont necessarily want to be gay...but ii cant help it!!!!???? maybe ii am bi since im ually attracted to SOME guys how can i tell for sure?....shouldnt u Just NO if u fancy guys completely? :( ii need help !!! thanks =D ♥....