pay by another company

Hi, every one. Here is my situation, pls help me.
I work with TN in A company which kinda related with B company.
Anyhow, I will move to B company within couple of weeks.
But A company will pay my pay for next 4 month until my current project finished and then, B company will pay after.
I told B company I suppose to be pay by the company my new tn visa employer. But B company said they will not know about that and don't need to too worry only 4 months pay.

Q1. Do you think I'm O.K. if I get the pay from old company?

Q2. How they know whether I pay properly or not?

Thanks in advance.

In theory it could be a problem because they're supposed to notify USCIS when you stop working for them, but it sounds as though you're not actually doing any work for them directly but they're still paying you. Well if they want to pay you for not working for them then there's no problem.

USCIS don't know about the pay frankly and the IRS aren't going to care so I wouldn't worry about it.

Thank you so much steve.
I feel better now.