Issue with Blog Links!

Hi All,

I am facing an issue with my blog posts links. Someone told me that blog posts links should be link this website.com/blog/postname.

But my posts URL are like this:
https://www.thinwithin.com/greatbodyresults/
https://www.thinwithin.com/becomeaweightlosscoach/
https://www.thinwithin.com/3-reasons-why-diets-dont-work/
https://www.thinwithin.com/quickweightlossresults/

Is this a big issue or there is no problem. Please update me ASAP.

Thanks for help in advance.

Regards
Marna