Hello Dr. Rynne, This Morning I Had A Strange Sensation

Hello Dr. Rynne,
This morning I had a strange sensation on the bottom of my foot, in the middle of my arch. It felt as if I was stepping on a smooth stone. I looked but there was nothing underfoot. I dressed for work as usual but throughout the day that same sensation returned. It was intermittent. I took off my shoe and saw nothing unusual. At the end of the workday I took my usual mile or so walk with my dog. By that time the sensation was coming and going on a somewhat regular basis. I am a fairly healthy middle-aged woman with a healthy weight. I have not been doing anything lately out of my ordinary. The best way I can describe the sensation is that it was a very slow pulse, going up and down (filling up and draining?) over and over. I have had no trauma to my legs or feet and I do stretch often. I work at a desk all day but am otherwise not a sedentary person. At this time the sensation has stopped. When it was pulsing earlier this evening, it would do so whether or not I had shoes on. The sensation did not hurt. It was very fleeting. I have never experienced anything like it. Any thoughts would be appreciated. Thank you. Janine