Should I take Plan B if birth control pills have been problematic in the past?

Patient: Last night, after my boyfriend and I finished having sex, we realized that the condom broke and he had ejaculated. Currently, we don’t use any other form of birth control other than condoms. My last menstrual cyle began 10.19.11 and it ended about 5 days ago. My cycle is approximately 32-38 days long. What are the chances of pregnancy? Also, I have had a lot of problems in the past while trying different types birth control pills, rings, and patches (severe nausea,vomiting) and my gynecologist suggested not using these. Should I take Plan B since using birth control pills,ring,patch have been so problematic in the past?