worth holding

I have held a little stock of PMA shares for a while. I now have a small (very small) profit. I feel like selling and get into something with better growth. The thing is, I always seem to sell when it is about to go up and get in when it is going sideways... I would appreciate your thoughts.
This is my first post here. I am only a casual investor without experience. I have been relying on magazines for my informations, I have just discovered this forum and find it very interesting.
Cheers,
Gege