Question about determining the parsha

Hello, I had a question about when a calendar lists the parsha. For instance, chabad.org lists this week’s parsha as Shemot. Does this mean the first aliyah for Shemot was read at yesterday’s Shabbat mincha, then will be read again tomorrow (Monday) and this Thursday, and finally read in full this coming Shabbat? Does this hold true for anytime the calendar lists the week’s parsha, that it was what was being read during that week leading up to the full reading on Shabbat, followed by next week’s parsha being read (first aliyah only) at that Shabbat’s mincha? Or, does this mean something else? Thank you