Is Plan B necessary?

My girlfriend’s period started on July 27, and we had sex on August 2, which was Day 7 of her cycle (also the last day of her period).
We had sex twice:
Round 1: Used a condom from start to finish. I pulled out while still wearing the condom.
Round 2: Used a new condom from start to finish. I ejaculated inside the condom.
As far as I could tell:
The condom never broke.
It never slipped off or rolled up.
I held the base while withdrawing.
I didn’t notice any leaks or wetness outside the condom.
When I took the condom off, the semen was clearly contained inside it.
I’m mainly anxious because I’m wondering if, in the unlikely event there was some tiny unnoticed leak, sperm could survive until she ovulates.
Given all of that, would you consider Plan B necessary, or is the pregnancy risk already low enough that you wouldn’t recommend it?