Theoretically, condoms are 98% effective with perfect use. But, we're not all perfect, so the actual observed rate of effectiveness of condoms is, in reality, 85%. There's always the chance of it breaking or being used incorrectly, so I'd say it's a good idea to take the pregnancy test, plus you are at the right time in your cycle for the results to be accurate. Just know that you'll be OK either way.
If you do happen to be pregnant, there are people in your life who deeply care about you and will support you through this.