Can birth control shorten you period?

Answer 1

No, but that's because you don't get a period on hormonal Birth Control.

Hormonal birth control works by stopping your menstrual cycle so that you no longer ovulate, and thus in turn you no longer menstruate. The bleeding you get on hormonal birth control is a withdrawal bleed caused by the drop in synthetic hormones when going from active to placebo week. A withdrawal bleed may be shorter than your period depending on the length of your menstrual phase verses your withdrawal bleed, and withdrawal bleeds can be lighter too.

Answer 2

The pill can do that yes. Many women who have a really tough menstruation with lots of bleeding an pain have it easier when on the pill.