You may already know this, but just in case you or someone else doesn't -- get your husband to switch to loose boxer shorts and see if that helps. Many men wear their underwear too tight which makes them too hot in that area. This excess heat can damage the sperm and motility (so I have read). I do know couples, in person, that got pregnant only 1-3 months after the husband switched to boxers.
AND, for you, I read a book by a medical doctor who specialized in fertility who recommended that ladies trying to get pregnant should take a really good vitamin with extra minerals; actually the ones for pregnancy, but take them now.
Also, he recommended PURE APPLE CIDER VINEGAR as well; you can get that at health food stores. You can drink it as a Mineral Cocktail made of PACV (1 tbl) + 1/4 cup Pure Cranberry Juice + 1 cup cold water (you may add sweetener like honey or a substitute as desired). Some people also add a bit of PURE GRape Juice as well, if desired.
The APPLE CIDER VINEGAR can be added to any juice you like though; or to sauces (like tomato) and salad dressings or as a salad dressing as well. It has helped many people, so I am told; it's worth a try anyways ...