Now, that website is for San Diego but, while I can't personally vouch, I imagine that SD isn't the only jurisdiction with such a feature. With the marked increase in mail ballot voting these days, I just thought I'd pass along the info. It's my first year mail voting so I didn't know and I figured others also might not.
If your ballot wasn't received, you can still go vote tomorrow in person. If you work tomorrow and don't have at least 3 consecutive hours available to go vote, your work must let you off for 3 hours to go do so and, though I don't know the details, my understanding is that they have to pay you.
If you forgot to mail your ballot, you can drop it off in person at any polling place (I've heard that they have a drop box, no lines or waiting) or you can go vote in person.