is it normal to wear braces only for 2 months?!

Hi guys, i appreciate v. much ur answers to this one. i have several gaps in lower teeth as 2 molars have been extracted (one on each side)and my teeth started shifting. My dentist told me i have to wear braces for 2 months. I'am now wearing regular braces not the new quick-fix invisible ones. I have heard that the minimum time for wearing them is 6months to 2 yrs. Is it possible to wear them for 2 months or have i been scammed?