are we all lesbians?

ok so way back in the ancient times of bio class there was this time that we were discussing determining gender,while this seems like a semi interesting topic,seeing as how my bio teacher reminded me of something straight out of the jurassic era the topic left no great impression on me.i do vaguely recall her saying something about XX chromosomes losing a tail and becoming XY therefore male, so i wondered does that meant at some initial point in time if we were all female.Then there really is no such thing as a true hetero couple is there: cuz we're all lesbians ,only some of our sex changes came via mother nature (which seems much cheaper)
i'm sure my logic is highly flawed but come on,don't you seriously wonder sometimes if your man is on his period? Aside from hormoning males and their little tails that take up soo much of their time is the unfairness of being female! I Honestly think girls get the shitty end of the stick just because the guys get the stick.So guys are ever producing sperm and girls pretty much have a set number of eggs thus God that sexist bastard seems to be encouraging men to go forth and mutiply (sometimes a little to indiscriminantly while a woman must be faithful which ultimately sucks ass cuz men can be like donuts ( always needing a hole) but any ways unless i opt for the less natural sex changin which is wayyyy more expensive i guess i'm stuck in this gender. lesbian or hetero lesbian lol