Do you ever check Politifact after you see or read certain news?

Yes I do, BUT I take them with a grain of salt. I also check the site and do my own research. Many of these so-called "Fact-Check" sites get their funding from less than reputable sources. Snopes I know gets funding from Soros, Politifact is tied to a newspaper which has its own built in biases.
The BEST way to check facts is to do it yourself, don't depend on others to give you facts.

After certain claims yes. If it sounds something like a three year old would say, you better check it out.

A little research can save hours of backtracking ;0)