You are a wonderful person to be so careful and concerned. I think probably all is well. In case you are still worried, you can always get an x-ray done to make sure - since pushpins have metal in them, one would show up. My dog swallowed a sewing needle once - and thank goodness we saw it going down, all snarled up in some thread, so we were able to get him to the vet for surgery, and he was fine. But to give you a bit of encouragement about the pushpins - my cat Beauty loves to play with a bead about the size of a pushpin, but of course without the metal point. She carries it around in her teeth and never swallows it. She can even toss it in the air with her mouth and swat it with her paw. So your cat is, I think, dextrous and intelligent enough to know how to take care and not swallow the pushpin. But keeping them in a box (in a drawer?) would seem to be worthwhile. Hmm. Maybe you will have to go to those flat headed thumbtacks for use in your bulletin board, so that your cat will not be able to steal those already in use.