If I may…
The word that is translated as “virgin” in the English gospels comes from a Greek word that can also mean “girl.” In fact, in ancient Greek there is only one world for the two; that is, there isn’t a world for “girl” and another word for “virgin.” They’re both the same word.
Likewise, there is only one word for both “woman” and “wife.”
Looking at the culture of the day, it makes perfect sense. First of all, girls were married shortly after puberty in those days. Therefore, there was no need for a word for both “virgin” and “girl,” as they were one and the same. If a girl was a little girl (pre-pubescent), she was by default referred to as a “virgin.” And no, I don’t know if there was an exception for the pre-pubescent girl who had been raped. And I’d rather not go there anyway.
Likewise, since it was unheard of for a grown woman not to marry (apart from those who chose to remain virgins for religious reasons, such as the Roman Vestal Virgins), there is no word for just plain “woman.” There were words for “prostitute,” “concubine” and “widow,” these three being the only alternatives for grown women in that culture that I can think of now.
SO, bringing all this information back to the OP:
The word that we read as “virgin” in the gospels basically tells us that Mary was a girl/young woman of around marryin’ age. I’m thinking (and I’m certainly not alone in this) that Mary was probably no younger than around 14 and no older than around 16.
Matthew 1:18 tells us that Mary became pregnant before she and Joseph “had come together” (New International Version). The words “had come together” is a polite euphemism for “had made sweet love down by the fire.” So clearly Matthew is telling us that she was a virgin in the physiological sense, not just in the sense of “young woman of marryin’ age.”
As for whether or not Mary was truly a virgin and became pregnant without benefit of intercourse, regardless of what the gospels say: that is a matter of great theological debate, and I, for one, am not going to try to answer it.