Asking Your Boss to be Paid

Ok, so I nanny for a family- 3 days a week, 20 hours a week. I recently have not been paid for the last week that I worked 11/28-11/30. I was worried over the weekend bc since Ive started with them, back at the end of October I noticed that they tend to pay me a few days after my last day of work for the week. For example, my last day is Friday and they tend to pay me on Venmo on Sunday or Monday. Well i still haven’t been paid yet and I just need to know

1. Is it weird/rude to ask or remind them about payment? Would you do that?

2. If it’s not, then how should I ask in a POLITE way?