Share 'bisexulity and boyfriends'

my current issue is eally that I am sure that I like both sexes but that I am afraid that in case I might become a mother I might somday turn into a lesbian that does not really feel attracked to her partner anymore. Maybe I am actually a lesbian but don´ t know it. I tend to fall in love with boys and I fell atracked to them when they are aroused. How did you find out?