If you join the session with your video and don't see yourself in the session, there's a good chance that you may be visible in another video app.
Please make to close out any other tabs, windows, or applications that may be using your video/audio. This could also be the reason if there's an echo during the session.
Another reason could be that you are using an external webcam. Please go to your browser settings and make sure that you are giving access to the camera that you actually want to use during the ICwhatUC sessions.
If you have done the above steps and are still experiencing issues, please contact support@icwhatuc.com.