Question about post-spay?

I have a 7 month 5 pound Pomeranian mix puppy, She was spayed about a month ago, right after the spay she was having a really hard time going poop and was in extreme pain, I called the vet they gave me stool softener. I took her back two weeks later and they said she had a minor infection where the stitches were at and told me to put peroxide on it for a week two times a day, I did. Today I noticed that the bump is not healed, she is acting fine, eating normal, going to the bathroom regularly, and has as much energy as before. The bump is not hard, nor soft, its in the middle. It is not hot to the touch or red, and she does not seemed to be in any pain when I press on it. Is this normal? She is my first dog and I don't know what is and is not normal. I have contacted the vet and they keep telling me it is nothing to be worried about and does not seem interested in seeing her quickly. I am concerned that it could be a hernia or an abcess is that a realistic possibility? Or is it just something simple like scar tissue? Should I instist that the vet sees her sooner than they are willing to give me an appointment, or take her somewhere else? Money isn't really an obstacle I don't have alot but if it would be best I would take her to the vet without hesitation.