The single best thing you can do to ensure you're protecting yourself is to do a home fit test. Surgical masks, KN95s, N95s have generally the same kind of filtration layer; the essential difference is the fit. Is it sealing on your face with <10% leakage, even when worn for long periods and while you speak and make facial expressions? You can't really know this for sure unless you do a fit test.

It is pretty cheap and easy to do a DIY fit test.

Here's a video that explains how to do it with a trash bag, some Splenda, and a $7 nebulizer.

Here is a written guide.