So the heat and a/c work in my car, except the blower doesn’t....sometimes. The blower will work for a week then stop, they will start working again for another week. Any ideas as to why?

I’ve verified that the heat and a/c do indeed work too; you can faintly feel it. Im just really confused as to why the blower works for most of the time, then apparently doesn't, only to work again the next day. I'm thinking an electrical problem?