Newton won the Scottish League Cup with St Mirren last week and is on-loan to the end of the season.
"I don't know what will happen in the summer. If I have to move on, well that's life," he said in the Daily Record.
"I'm not naive enough to think I'm going to get flung straight into first-team football with Newcastle.
"If the option came up to stay with St Mirren, it would definitely be worth thinking about. I've loved my time here so far. St Mirren has got a wee place in my heart now.
"I don't know if it's the fans and how brilliant they were on Sunday or because it's the place where I got my first taste of first-team football, but this place means a lot to me now and I can see myself staying here."