"I refuse to answer that question on the grounds that it may incriminate me."
You can not be compelled to admit to a crime even if you are guilty. So, in a sense, the answer to your question is yes. However, pleading the 5th , as a tactic, could be employed for other reasons, such as protecting another person, throwing investigators off the scent, etc. So it is not always a slam dunk, it could mean other things.