The digestive system shuts down after 3 to 5 days for most people and probably for you, too.
If you are feeling hungry then you need to up the amount of juices you are drinking. Rule number one: Never limit yourself... drink drink drink. In addition to the juices, drink water and herbal teas. A cool trick (that most purists frown upon) but which works very well for situations like this is to sip HOT veggie broth made WITHOUT boullion and with raw veggies cooked down and strained. Or hot lemon/ cayenne pepper tea. The trick is the heat from the broth and lemon tea convince your belly you've eaten and are full. In addition, you can do this with fruits too, making lush hot fruit broths. I usually abandon these broths after the first week as I have no need for them anymore.
Another trick... drink lots of GREENS in those juices. If they are too bitter for you disguise them with apple/carrot. I drink my juices undiluted in 16 ounce glasses. I juice 8 ounces of greens and 8 ounces of carrot/apple and yummmm... down the hatch it goes. The greens are powerful and will coat your nerve endings, give you stamina, quench the hunger pangs, protect during detox (and speeds up detox because of the high chlorophyll content in the greens) and heal right down to the cellular levels.
Rule of the thumb drink more water than juices, more juices than herbal teas and more herbal teas than broths. But never ever limit yourself the amount of juices you drink. If you drink 3 glasses a day and still feel hungry drink 6 glasses a day, 8 glasses of water, 4 cups of herbal teas and 2 cups of broth. This is an example. Play it by ear, listen to you body, and go from there.
Here's a link that will take you to several excellent articles on juicing, fasting, breaking the fast, detoxing, juice recipes and the like: http://curezone.com/blogs/m.asp?f=573&i=78
I hope this has given you some ideas...