Pregnant Shih-tzu, brown discharge?

Question
QUESTION: Hello! this is the first time I'm dealing with having a pregnant dog, and it is also her first pregnancy, she is a 4 year old shih tzu. I dont have any experience except for reading facts online, and she has all the symptoms of being pregnant, we havent taken her to a vet though.
Assuming that she is pregnant for sure, she'll have been about..50-60 days pregnant, it began on november 20th 2010.
Before i noticed clear jelly like mucus stuff coming out of her private part. I've read that was normal, but yesterday (Jan 12) i noticed that she had brownish discharge/mucus out, but it was dry by the time i noticed it. What does that mean? is it the mucus plug? if so, what exactly is the mucus plug and what happens????
is it a bad thing? some told me that it could be signs of a miscarriage, her belly is still big, and she seems like a normal pregnant dog, i just dont know what the brown stuff is and would like to know. Also,
when can i expect her to give birth? i want to be there for the birth, so im missing school for it, i jjust wana know around when I can do that. Please help asap!

ANSWER: Between 50 and 60 days is a huge difference. Gestation is 63 days for a bitch, so you understand why I say there is a big difference between the days. I would suggest that you take her to the vet and have them do an x-ray to determine if she is pregnant and if she is how many puppies you can expect. This is very important. If you don't know how many puppies to expect, you won't know if there is a problem if a puppy gets stuck. The vet will be able to guide you from there on how many days you have to get ready and what you will need to do in case of an emergency.
Good Luck!

---------- FOLLOW-UP ----------

QUESTION: Thank you again for your response :)
I want to take her to a vet for a checkup, but she won't leave her puppies' sides. Not even to go to the bathroom, i tried to put her to go but she runs right back to her pups.
When is an appropriate time to take her to the vet, and take her to use the bathroom?
Also, i've read that she is supposed to have an appetite 2-3x more than before, but she isnt really eating a lot, only when i feed her, but even then she doesnt finish all of it.
Ive been feeding her cesar's wet food that comes in the little boxes, is that okay? she wont eat dry food so is wet food thats usually meat based okay?

Answer
If she needs to go to the bathroom, she will let you know. Otherwise just let her be with the puppies. Ceasear is not going to be enough protein and fat for the puppies to have the proper nutrition. She needs to be on a puppy food for the duration of the puppies nursing. I would suggest wellness puppy or nutro natural choice small breed puppy. If she is not heavily bleeding and there is not a cause for concern then wait to take her to the vet when the puppies go in for a check up.