Actually, it was called the 'Love Symbol' before Prince starting using it as his name; hence the 1992 release
Love Symbol by Prince and the New Power Generation:
http://en.wikipedia.org/wiki/Love_Symbol_Album
I think I was already aware of how it came to be (after him calling himself a slave to his record company) since I have a sister who use to love his music. I remember him saying in an interview there was no pronunciation for it and that it represented his name. After that I think people saw how it was the symbol for male and female combined to make one symbol and that is why they started to say it was the symbol for hermorphodite but I'm not sure.
Are you saying the combined symbol was there before Prince used it and it was being called love when it first came out? I never heard that but I can ask my sister some time, it was during that period she use to listened to his music so she should know.