Moggy,

Usually it takes a total of 10 hours for a cat to deliver kittens. She will also have spotting (which is what I think you see). The "lump" you feel could very well be her uterus. As long as she's not having any contractions and trying to push, I wouldn't worry. Unless she gets lethargic, isn't nursing her babies, stops eating, using the litterbox and has a fever, she's probably okay. When in doubt, call the vet.