SD memory card. I was using my camera with no problems at all - it was fully charged and took some

Question

I was using my camera with no problems at all - it was fully charged and took some pictures. When I got home and turned the camera back on, I got a message telling me the memory card was full. I actually at least 100 pictures left. When I tried to view my pictures, it told me that there was no image. Does this mean that I somehow lost all my pictures and if so, is it something I did?
Thank you.