If you had unprotected sex, it is always possible that you are pregnant, even if you used emergency contraception
(plan B). No contraception is 100%, even plan B, and the more episodes of unprotected sex you have, the higher your chances of becoming pregnant. However, it is also possible for the hormonal therapy used in emergency contraception to cause nausea. Overall, the best thing for you to do in this situation is to see your primary care physician
right away for a pregnancy test and possibly a pelvic exam. It would also be a good idea to be screened for sexually transmitted diseases (which can be done with cervical swabs during a pelvic exam for chlamydia and gonorrhea; HIV and hepatitis require blood work) because unprotected sexual contact also places you at risk for a number of diseases that can have significant effects on your overall health. In addition, you can talk to your doctor
about finding a method of protection that will work for you, as it is important for any sexually active adult to be able to protect himself or herself from unintended pregnancy or disease. The only way to prevent transmission of disease is barrier protection, but a method of hormonal contraception will also help make sure that you only become pregnant when you are ready to do so. Again, please speak with your doctor.