Condoms do not prevent pregnancy 100% of the time.
It is possible that you could be pregnant. But, if you are, it will show up on a pregnancy test. Sooooo, take a test.
Because you are using condoms, I will assume you do not want a baby at this time. You know that terrible sinking feeling you have over the thought of being pregnant? You don't want to put yourself through that every month because it will drive you nuts. Well, should your period arrive, you may want to consider getting on birth control pills and take them every morning when you brush your teeth. Taking a pill while doing another routine thing, such as brushing your teeth, will get you into the habit and prevent skipped dosages.
Please take a pregnancy test so you can have some answers to your concerns.