Nervous & Confused

I have a very irregular period where sometimes I haven't gotten my period for 1-3 months at a time. I have a boyfriend and we use protection every time we have sex. I haven't gotten my period for 2 months now and I'm starting to feel anxious. Even though we always use protection, I can't shake the feeling of the possibility of me being pregnant. I have yet to take a pregnancy test because I'm afraid it will be positive. What should I do?