I am planning on donating sperm to a couple wanting to have a baby. We decided to do it the "natural way" without artificial insemination.

I'm completely okay with doing this since I decided a long time ago to not have children, figured If I could donate and give someone a gift I chose not to have would be a blessing, plus she's beautiful!

My question is: what form of agreement should I have signed before the pregnancy happens? I don't want to be responsible for child support or anything after she become pregnant. I discussed this with the husband and he agrees. I just feel comfortable doing this with a sign agreement PROTECTING ME from any financial burden etc. that could happen if I don't protect myself legally.