You need to stop thinking of getting your wife pregnant and get back in to the romance, and why you guys fell in love, have some fun. She could also get the ovulation kits to help pinpoint when to have sex. If just getting back in love with each other, not having the pressure of having a baby will help you with your issue. And there are medications you can ask your doctor about. Wear boxers.
If you're wife cycle is regularly then try 8, 10,12,13,14,15 day sexual relationship,
If everything is normal u must conceive,