Is it normal for CPS to call ahead of time?

Is it normal for CPS to call ahead of time to set up a visit? I thought they generally just showed up unannounced. Someone called CPS on us with a bunch of lies and that my toddler is deaf and not potty trained. They called me Friday to set up a visit for today. I found it unusual. But it did give us time to make sure we had nothing they could hit us for. Just getting a heads up was unusual.