Consider the following translation:
Hasta que tomé la píldora no se me quitó el dolor.
Until I took the pill, the pain did not go away.
Now, this Wikipedia article on Mexican Spanish says the "no" is often omitted in such constructs as the sentence inherently implies a negation. So, according to that article, a Mexican would just say:
Hasta que tomé la píldora se me quitó el dolor.
My confusion is, won't the sentence also get interpreted as "by the time I took the pill, the pain went away"?
If not, how would a Mexican speaker say a sentence involving the phrase "by the time"? I am also curious to know if this omission of "no" is a common feature throughout Mexico or is it just a regional phenomenon. If regional, which parts is it common in? Is it considered "uneducated" speech in those parts?