Download a free Wi-Fi analyzer App on your mobile device. Let the app run for roughly two minutes, and you will be presented with the results of the wireless channels around you. The graph will indicate the various Wi-Fi channels along the bottom, and your specific wireless channel your router is using.
If you are picking up multiple channels and they are overlapping your signal, it would beneficial for you to log into your router to change the Wi-Fi channel. Overlapping of the wireless signals can cause slow speeds and dropouts on the connection.