When a condom breaks, it breaks completely, from top to bottom. It's not just a minuscule hole. There's no way you wouldn't notice if it had really happened.
PEP is not intended to be used every time you get scared. PEP is generally intended to be used when a person has had a high-risk encounter with someone who is known to be HIV+. PEP can have serious side effects.
When condoms break and expose the head of your penis, it is OBVIOUS. You would not wonder if it happened or not.