To add to this, home sperm test kits can help rule out the man as well. Some men don't know to avoid vigorous exercise, hot showers, and jacuzzis until they realize how low their sperm counts actually are. (The below kit isn't the only kit. Shop around if this is pertinent to your interests because I don't want to feel like I'm shilling this specific one).

https://www.amazon.com/YO-Android-Description-Compatibility-...