Injuries

What’s the chances an injury from when my husband was 5-6 years old would affect our ability to have children now? I have a daughter from a previous relationship that he’s taken in as his own but now he wants more children. He fell off of a bike and the handle bar hit one of his testicles pretty bad from the stories I’ve heard from him and his parents. Or could it be something else? He’s eased up on smoking cigarettes. Maybe has one or two a day now. Doesn’t drink alcohol. Gets plenty of exercise. He smokes marijuana (in a legal state). He’s in his mid 20’s. We’ve been trying for months with no success. Any tips would be wonderful. We can’t see a fertility doctor yet so that’s out the window. Thanks in advance.