My friend, it’s hard to know if you would get pregnant or not when you have an unprotected sex. But note that if you do have unprotected sex, you are at risk to get pregnant becuase the man's sperm has the chance to fertilise a woman's egg. If you do not want to get pregnant, you should think of abstinence or use a condom because the latter protects you almost 100%.
You can on other hand got to a nearby health center so that they can explain to you what to do to avoid getting pregnant in case you have sex. Then for you to know if you got pregnant in case you have already had sex, normally, a clear sign is that you miss your periods. In this case you should go to the health center for a pregnancy test.