Should I Be Worried That My Cat Hasn't Gone Into Labor Yet?

My cat's abdomen dropped 2 weeks ago and her nipples are completely full of milk, she hasn't gone into any of the stages of labor (licking her genitals, loss of interest in food, drop in temperature, loud yowling, etc). She is still very active, and even caught a bird and killed it today. She looks like she should have given birth already.