Glad you caught it before it all went down the hatch!
I had a HUGE scare! We had just gotten a new kitten about 12 weeks old. I had been sewing the binding on a quilt, I got it finished about 10:00 one night. When I was done I stuck the needle with the bit of thread that was left into the spool of thread and put it with my sewing stuff. About 3:00am I got up to feed the baby and noticed that I had not put the lid on my sewing box I went over and noticed that the thread and needle were missing. I freaked out. I checked ever inch of the floor near my sewing box, searched every inch of the house could not find it anywhere. As soon as the vets office opened the next morning I called and took the kitten in for an xray because I just KNEW he had swallowed that needle and thread, but he hadn't. I came home and SEARCHED the house some more. NEVER did find the stupid thing. about a week later after searching every day for the needle and thread I realized that I had stitched the thread on with a lighter color thread than I had quilted it in and I had been looking at the quilting thread the whole time, the needle and thread were still in the thread that I had actually stitched the binding on with! LOL
Don't beat yourself up about it, just make it a lesson learned!
Also everyone with cats be careful about stings that you clip off while sewing. If a cat plays with and swallows them they can cause an obstruction and the kitty runs the risk of needing surgery to remove it even though there is no needle attached.