Am I doing the right thing?? Found Dog

I was going back and forth between sending this dog I found to the animal shelter or keep her a couple days, put up fliers, see if I get a response and if not then send her. I would be worried sick if my dog was out there and would most likely check the shelter. However, if someone was close to me I would appreciate if they found her, put up fliers, and spared me $150+ to get my dog out of the shelter.

I posted on Craigslist and a site that posts to Facebook for you (I don’t have social media so had to go through a website that connects to it) and put up fliers around where I found her. She was running in the street so I didn’t want to leave her. I resolved to keep her until Monday, if I don’t hear a response from anyone, I’ll take her to the shelter because I can’t have another dog. (We have two). She’s very sweet, gets along with my dogs, and doesn’t cause any problem. (I was a little worried about possible diseases she could give to my dogs but she seems very healthy, older, and not underweight).

Am I doing the right thing or should I take her right away?

(Oh and I am taking her to check for microchip tomorrow and also know to have anyone calling provide information to verify owner) I don’t want to cause anyone to worry but I want her to be safe. If I send her to the shelter and she doesn’t have a microchip she will have 5 days before she is either available for adoption or put on the list for euthanasia.