Some companies may not accept the two week notice, and may ask you to leave immediately. This may be true even if you have a good manager or relationship with the company.

When I quit my job, I intended to give four weeks notice, and to offer to work part time for a month later if they wanted it. Manager took the offer to their upper-management, upper-management came back and said, "nope, two weeks max."

I had prepared for that, but did not expect it, at all. Generally speaking you should only give notice if you're also willing to leave that day.