You are a deep thinker. I can help you out. Here it is...stop thinking about that. No but really. I’m saying this as a friend in Christ, as someone who really wants to help. How about think more of, “Is it good or evil, is it right or is it wrong”? Maybe it will help to think of it that way instead of natural and unnatural. God made this world to function as it does...we are to ask others for help when we need it, go to a doctor, yet still expecting a miracle from God. Go to a dentist; buy our food at stores, and go to work… We have to call for a plumber, an electrician, a roofer… That is just natural ways of the world. If we concentrate too much on natural and unnatural, we might not be able to draw the line between good and bad. I want to eat natural foods, but I do not want to eat dirt, which is natural.
You are right, anything a man can think up and do could be considered natural, or how else could he do it? However, but is it right? We are not doing these things supernaturally. It might be natural to not be able to conceive, and natural to conceive, and even natural to conceive by way of a test tube baby…but is it right? What do think? Did I help?