As much as I hate to say it I think the Dr is the next step. Your dr can do some basic tests on both you and your partner to check everything is behaving as it should. If the tests come up OK perhaps you could try and find a naturopath that specialises in fertility (I'm not sure where you are from so can't suggest anyone). The Jocelyn Centre in Sydney may be able to refer you to someone in your area. Good luck, don't lose heart.