It is most likely a very small birthmark, because it was very small when it was born, so it cannot be seen. And birthmarks will increase with age. Some birthmarks that are lighter in color will gradually fade as they grow older. However, because your child is still relatively young, it is recommended that you take your child for a checkup regardless of whether it is a birthmark or not. After all, you should not be careless about any problems with your child.