It sounds like you are in need of some guidance. Not all dogs bleed heavily but you want to protect your furniture and carpeting. The hole in the panties is probably not for pooping but for her tail. These panties are most likely made for several types of small breed dogs, some of which might have long tails.
I strongly suggest that you get her spayed as soon as you can after she is safely out of heat. I have very strong feelings on this subject. I know you love your dog and unless you know what you're doing it is very risky to breed dogs. Even when you do know what you're doing it's risky. Often times nature needs a lot of help and I'm sure you don't want to lose her.
The more times your dog goes into heat the more risk she has of developing pyometra, which you can read all about here:
http://www.thepetcenter.com/sur/pyo.html
Years ago due to our ignorance, our five year old yorkie, Cecily died from this and it didn't have to happen. I hope sharing her story will keep others from the heartbreak her loss caused our family.
Your dog should not be outside without you. Even in the best fenced in yard, a big dog can easily get through a fence. The drive to mate is very strong. A tiny dog outside without supervision also makes an easy meal for a hawk or owl if you have those in your area.