Vertical bricks ("soldier arch") are supported by a cavity lintel, which I assume was used..........
https://condell-ltd.com/lintels/cavity-wall-lintels/ig-lintel-l1-s-100-3600mm?gclid=Cj0KCQjw94WZBhDtARIsAKxWG--wHuFRAs5jCMZlEIIsdDcVMJFEwVdRgK-WHyI7VnWLPC3ewbJ_iYsaAlSyEALw_wcB
Can be a soldier arch or even normal brick coursing (bricks laid flat as per the rest of the wall.)
Looking at your brickwork, I imagine you have a cavity?
Also known as a "flat arch", it's possible to create a load-bearing arch like this without any lintel at all, but it gets a tad more technical.
You sometimes find what Ken describes as well. A substantial 4x2 frame with maybe a 6x2 timber over that helps carry the load.
Whether you have a steel lintel or not depends on the age of the house. Other than that, it's hard to tell.
Either way...... you're ok :o)