This is a difficult area, and is best answered at some length by an ethicist. It is not a question that has a black and white answer, although there are some clear guidlines. The question has too many permutations to be answered in this forum.
If you ask tha Apologetics section, you might ask for a referral to the Catholic bioethics group, as it becomes a very specialized response fairly quickly, particularly if this is a personal question as opposed to a general guidelines question.
If it is personal, my prayers are with you. Getting the T-shirt wasn’t much fun.