Weird ultrasound

At my ultrasound yesterday we clearly saw the baby's heart flickering away and right under the gestational sac was another flicker in a circular sac like area. The tech was like wait a minute, what's that? It looks like another heartbeat. Upon closer inspection and visualization of the beat pattern of the heartbeat she concluded it was my heartbeat. I about crapped my pants. Has this happened to any of you? This is my 6th child and I've never seen my own heartbeat in my uterus. I've circled the area in purple.