I've taken ortho tricyclen lo for 3yrs. my cycles are normal & short. 3mos ago, it lasted 2 wks and for the next 2mos folliwing that, i didn't even get a period. should i be worried about pregnancy or considering a different birth control medication?

Rule out pregnancy: You should always rule out pregnancy. And talk to your doctor about your problem. It is common to have irregular periods on a pill you have taken for years. Sometimes it will go back to normal again, so you could stay on the same pill. Sometimes it doesn't. Everyone is different.

PG test first: First do a pregnancy test and if negative then see if the Tricyclen continues this pattern for the next 2 months. If it does, then talk to your GYN MD about plan going forward.