I missed almost 2 weeks of my birth control pills and had sex with my boyfriend a week before school started in September. I have since been back on my pills but haven't gotten my period yet, he pulled out before ejaculating. I've felt like throwing up after eating certain foods but it's happened before, I took a test about 2 weeks ago and it came back negative but still no period...is it possible I'm pregnant?? I really need help with this, I'm a senior in high school.