Swallowed a plum seed

I was eating a small plum about the size of between a nickle and quarter and I accidentally swallowed it! I called my surgeon and talked to the nurse and she said to look for pain in either the upper or lower part of my stomach. That was about 3-4 hours ago. Nothing so far. I am praying that nothing happens from this. Has anyone ever swallowed something like this? Please respond. Thanks Crystal