Thank you so much for your question. It is my privilege to be able to help you.
It is very unlikely that youy would get pregnant after touching only your clitoris, especially if there was only a small amount of semen on your finger. However, it is not impossible that a drop of semen got into your vagina and could make you pregnant. Although it is unlikely, if you really do not want to get pregnant, you should consider taking a morning after pill to prevent pregnancy, unless you are already using birth control.
I hope this was helpful to you. Please remember to ACCEPT this answer if it answered your question so I can get compensated for my work. If you have any more questions please feel free to ask me. Take Care, Dr. SaulJE