Was the author of Matthew who first translated Isaiah 7:14 as "virgin"?

Matthew 1:23 famously reads:

All this took place to fulfill what had been spoken by the Lord through the prophet:

“Look, the virgin shall become pregnant and give birth to a son, and they shall name him Emmanuel,” which means, “God is with us.”

This is one of the most disputed topics in the entire Bible, but one common concern is that the word παρθένος (parthenos) is not the best translation for the Hebrew world 'almah.

Usually the response is that Matthew is simply quoting a pre-existing Greek translation of Isaiah, the famous LXX. But as far as I can tell Matthew is the earliest text containing this translation.

Do scholars believe Matthew was indeed working with an earlier translation? Is it possible that Matthews translation is what ended up influencing the Greek text of Isaiah that we have today?