I rescued this cat from horrible people and she was pregnant... the first possible time they said she could've conceived was exactly in the middle of may.. it is now August 4th and she is 10 months old... for the past 2-3 weeks her nipples are pink and her milk sacs are full but no milk comes out her belly is ginormous and I have been able to feel the babies moving for the past two weeks.. she eats a few bites of food every 30 minutes for the past month and she's been licking her belly and genitals for a day or two now.. her vagina is pulsating with contractions and her belly jolts every ten minutes from time to time.. she isn't in pain and she won't stop sleeping and purring... guys I'm at a loss I have birthed many kittens and bottlefed many litters but I've never seen this.. all the litters I've dealt with we're pretty quick and didn't take more than two hours... please help me if this is normal or bad please let me know and also at 3:00 pm today I noticed discharge and her anus has black stuff on it.. it is now 7:30 at night and she's still panting but weirdly not in pain... and she constantly rolls over on her other side all the time thank you all for your help

A cat pregnancy lasts for about two months.

Just leave her alone. It sounds like she's very close to delivering. Has she been looking for a dark, quiet place to have the kittens?

Cats have been having litters for centuries with little help from us humans.
If she isn't in distress I wouldn't worry so much, make sure she has a secluded, quiet area that she is comfortable in to have the kittens and keep an eye on her.
Cats can actually delay labor for up to 24 hours if disturbed or uncomfortable.
The black substance on her rectum is likely anal gland material that has been expressed by the pressure of her pushing, if so, nothing to worry about.

Here is some good information to read while you are waiting for your new arrivals.
Giving Birth to Kittens (http://www.marvistavet.com/html/giving_birth_to_kittens.html)

She is sitting next to me... she was sitting Ina cubby half full of my clothes for about the past week and a half... she was sleeping on my bed till I got up and sat Ina chair now she's right beside me and wide awake