my dog rubs her butt on the carpet by dragging herself with her front feet. i thought it was normal but my mother says it means she has worms. is this true? what are the symptoms?

okay so im like 90% sure i DON’T have worms, but i get REALLY paranoid sometimes when people around me get stuff.
a friend of mine has a dog who has worms, and i usually play with the dog a lot because hes really friendly and i throw frisbees and stuff to him.
but i heard my friend say that worms are contagious and stuff, and now i wanna be sure i know what to look for.
how do i know i need to go to the doc?
would i see worms in my stool, or some other symptoms?

1.Listless&Weakness
2.Persistant diarrhea or thin watery bowel movements with or without blood in them
3.Bloated stomach, especially in puppies
4.Dry,coarse, chalky coat
5.Persistant vomiting, with or without worms in it
6.Loss of weight and dehydration
7.Sleepiness and loss of vitality
8.Increase of appetite without growth or weight gain
9.Great decrease of appetite and lack of interest in food
10.Frequent rubbing of body and hindquarters against the floor
11Frequent chasing of tail, and biting at base of tail,and anus
12.Fainting spells after sever bout of coughing or vomiting
13.Excessive thirst
Hope this helps!

Worms???

when he coughs up the blood it looks like hes coughing up his insides. im taking him to the vet in the morning but i wanna know what im up againts.