The Tarot card associated with Pisces is The Moon. It's a difficult card to comprehend (kind of like Pisces). It can suggest confusion or deception (things always look different by the light of the Moon). Something you're not seeing. Fear of the unknown.
But it can also be a call to follow your instincts and explore your dreams. It is strongly influenced by the cards around it (just as the actual Moon reflects the Sun's light), so clarifying cards are recommended.
If you pull the Moon card, something is not as it seems on the surface. You need to look deeper. Logic is not going to help you; close your eyes and go with what you feel, rather than what you know.