Sorry, but confused by the title. Do you mean you know think you're bisexual, cause that's a little confusing considering you slept with women (and I assume men considering your partner is a man too.)
I'm a bi woman, but if you're not attracted to your male partner, I wouldn't necessarily make the straight jump to assume you're fully lesbian just yet. Did you feel compelled to date your partner due to societal pressies once you left the uni environment?
Also, have you NEVER felt anything for your partner? That's more concerning if you haven't. Your child WILL pick up on that as they grow older if both their parents don't love each other