Sounds like she might just be slow getting started. I wouldn't panic yet. I had a cat years ago that gave birth to 8 kittens, her plug came away 3 days before she went into labour. Everything went well though and all kittens were fine.
So she startedmeowing at me a lot this morning i sat with her by my bottom drawer and what do you know we currently have 3 babies and shes still in labor from what i can tell its been about 30 minutes since the last one.
I have food and water i been offering it to her but she is ignoring it shes currently laying on her stonach and breathing really heavy again with some contractions.......