Can I Get Pregnant While Using Loestrin Tablets?

i was on orthotricyclen lo for a month and it wasnt helping my ovary pain as much as the other one i was on last ear for 3 months ( loestrin ). So after i finished my first pack of orthotricyclen lo i switched right over to loestrin fe 24, (my doctor said that i could switch to it right after i finished the other pill) to but ive been having sex alo with protection and once with no protection, is it possible that i could possibly be pregnant ? because my last period was dec 3 and i was suppose to get it december 29th to janurary 1st but i have no period symptoms or pregnancy symptoms. ive felt completely normal for the last 7 days that i was suppose to have my period. i just took the first white pill of loestrin today, this is my second pack of loestrin. what do i do ?