Am I OK if I have sex? Can I have sex? I am so scared.
Whether you are able to have sex depends on how far your body has developed. Basically, if you are able to ejaculate, then you are able to have sex.
However, whether you should have sex is a different question. The Bible teaches that sex outside of marriage (called fornication) is a sin. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). There are all sorts of reasons why God said not to have sex before you are married. Many are covered in Why Sex Outside of Marriage is Wrong. As an example, no matter what precautions you take, having sex means there is a risk of getting a girl pregnant. I don't know how old you are, but are you ready to take on the responsibility of raising and supporting a child? Because you have control over where your penis goes, you are responsible for any child you cause to be conceived. Currently the laws require the father to be financially responsible until the child is 23 years old.