I don’t know how common this is, but where I live (PNW), our city water has more than one source, and based on a number of factors, the water running to our house may have its source changed for short periods of time. Have you talked to any of your neighbors to see if they’ve experienced something similar? You might try reaching out to the city water department and see if they have any idea what it might be as well, they may even have free (or cheap) water testing you can do on water from your house.
Unfortunately I don’t have any real answers for whether your water is safe to drink or not, but hopefully something here will be of some help to you.