I wonder why is it romanized to "do", when it's read as "da"?
As the preposition is so small, it's considered together with the following word, which in the genitive has its stress on the "а".
As a side note, Russian pronunciation is remarkably uniform compared to languages like English. Dialects do exist but in practice the vast majority of speakers will pronounce things very similarly. The phonetics are also so different from English than the typical English speaker will not pronounce any Russian words close to native pronunciation.
AFAICT, that goes for absolutely every other language too. Nothing even comes close to English for inconsistency in pronounciation (and even more so, spelling).