Random repeated behaviors such as you are describing are very common for many people, and are usually not related to a hidden diagnosis in people who are high functioning and otherwise well. Many people will have some similar behavior that they perform at times when they are not thinking, and some psychologists would perhaps argue that they are residual comfort behaviors or some other persistent behavior that has been retained from the past for some reason.
Unless you have other symptoms of autism or another medical or psychological condition, a small, non-intrusive behavior such as this should not be a cause for alarm. If it begins to interfere with your daily life and begins to detract from your ability to perform in public, for example, it is something that could be discussed in more detail with your family practice doctor
or primary care doctor
, who would be able to ask further questions and determine who would best be able to help you further.
Otherwise, you could speak with a psychologist
if you are concerned for any other reasons. Either one would be able to normalize the behavior if appropriate, or treat it if needed. But, again, this would be an unusual age and sign to note the beginning of autism.