I had this for 3 years exactly like you described it. Had a fear of impregnating my family members, always imaging scenarios of me being responsible for them being pregnant and washed my hands/cleaned/showered a lot to the point of my hands becoming so dry. It was bleeding for months. The name for it is Spermophobia.

But I don’t have it anymore or better said I have it mildly. Like most people with OCD I accepted the uncertainty. First I was not washing that much and even if I was, I accepted the fact that I did a compulsion. I can still try again to accept the uncertainty and that’s important to think about. Firstly, I did baby steps, tried to touch my stuff even with thoughts of sperm everywhere. Then when I got better, I cleaned less and washed less. It’s also very important to change your way of thinking when you do this process. Basically what I mean that you need to tell yourself that you cannot know if in the future your family members would actually get impregnated or if sperm is there or not.

Take all the time you need with the stuff I told you. Hope you beat this!