Speaking with your partner about an issue

Okay so I'm in a new relationship with a guy who I love dearly he's an amazing man he accepts my two kids that are not his he's been nothing but good and supportive to me with everything and I fell in love with him my issues is I do not know how to bring to his Attetion about a lump I found on one of his testicles I'm kinda scared I love him very much we both want to have a child together he tells me he loves me but for some reason I'm scared to bring that to his Attetion I do not know how to go about it we haven't gotten pregnant yet so I do not know if his lump is the cause of that or what I need help I have looked it up on line and all but I just can't find a way to tell him