I thought that there was a kitten left to be born after my last litter, I was sure I could feel a lump, but 12 hours later there was nothing to feel, so I know it was the womb contracting.

In another litter I was sure that there was a kitten left to be born and there was, he arrived safe and sound 28 hours after the others. The Vet had said it was fine to wait for 24 hours between kittens as long as the queen was calm and happy - which she was. That time I continued to be able to feel the kitten moving inside her, it was clear the kitten was there, so if you can't feel the lump now hopefully there isn't another.

Congratulations on your newborns