Should I change birth control?

Taking Yasmin & having a different experience than last time ? I was put on Yasmin a year ago to regulate my periods and it worked perfectly for me! I didn’t have any of the side effects when starting either. Now I’ve been off for a year and had some extra packs lying around, & after having unprotected sex 3 weeks ago, I started taking them as a precaution. Now my boobs hurt, I feel nauseous, and my face and back are breaking out. I don’t understand why I’m having a different reaction to the same pills a year later?