Changing birth control pills...ovcon 35 to ortho tri cyclen lo?

i was on ovcon 35 for over 10 yrs and the doc recently changed me to ortho tri cyclen lo. i actually took my first pill today....im a lil nervous cause i been taking one brand for 10 yrs and my body is used to it and i know when and how i get my perios but the doc said i didnt need all those hormones so he changed me to a lower does and i am nervous....any input???