To be honest, if you are continuing to set new PR's, I would say that you should definitly NOT change your program. Don't over-complicate things just because other people are doing it. When your gains start to plateau, change things up. In my opinion, this easiest way to learn how to change things up is just to cycle through strength, power (explosive strength, strength-speed, etc) and endurance.
Right now are you primarily focusing on max strength (1-5 reps with high weights), explosive strength (1-5 reps with sub-max weights or oly lifts), or strength-endurance (8+ reps)? Obviously there are a few other qualities that can be trained, but those are the ones that most lifters focus on. If your maximal strength numbers have leveled off, you probably need more explosive strength (to speed through that sticking point), or strength-endurance (to strain through it).
Other things to consider that are fairly easy to change are your "method" of lifting. Do you usually use a traditional bench press? If you start to level off with that, try some pause-reps where you bring the weight down and hold for 3 seconds on your chest and lift (hint, use less weight!) or some heavy eccentrics where you slowly (3-9 seconds) lower a supra-maximal load. Finally, make sure you switch up the movements themselves.
That is, try close-grip benches, snatch-grip deadlifts, close-stance or powerlifting stance squats, hammer or reverse curls, etc.
But to summarize, you always want to be addressing your weaknesses. As a beginner, it will be hard for you to do that because you're most likely weak at EVERYTHING. In my opinion, if you just keep switching up at random, you will never really learn your body and learn your weaknesses and how to address them.
When your gains start to stop, think about why they did. Do you have trouble fighting through a sticking point (not enough strength-endurance) or are your lifts slow, even at 85-90% of your max (not enough strength-speed).
That's just my .02