Unusual clouds looking like missile launch

I had gone into my bathroom to take a shower and looked out the window to the southwest. I saw this unusually long cloud that had a separation about 2/3 of the way up and many broken clouds below. It looked like a missile launch.  As I watched it grew longer as it slowly moved across the sky without changing shape or breaking up.  I thought it may be a missile launch as I can and have watched them go off from Vandenburg AFB.  So, I checked the missile launch schedule and there was nothing scheduled today.  An Atlas 5 is due to go off from Cape Canaveral on the 13th and there is a Chinese Long March that has yet to be scheduled and a Falcon 9 to go up on the 14th-15th from Kennedy Space Center. The clouds appear to possibly be a Vega from French Guiana but there is nothing from there scheduled until 16th-17th. An Electron is due to go up on the 15th-16th from New Zealand. I began to wonder if it is from an unscheduled launch.