I'm worrying, sir, about my girlfriend. I am sure that no sperm came out during sex. I controlled myself to avoid pregnancy.
Technically, it only requires one sperm cell meeting up with a woman's egg cell to cause pregnancy. To increase the odds of this happening, God designed your body to release a large amount of sperm with each ejaculation. The typical healthy male releases about 500,000,000 sperm cells with each ejaculation. Each of these cells have vibrating tails which allows them to move on their own and a chemical sensing mechanism that guides them in the general direction of a woman's egg cell. Once your sperm is within your wife's vagina, it is able to survive up to six days in its quest for the egg cell. Yet with all this beneficial aid, the typical married couple trying to conceive a child has an 85% chance of conception in one year. In other words, in one year's time 85 out of 100 couples having regular intercourse will conceive a child. It is really a gamble; it could happen the very first time or it could happen after the fiftieth try.
Because of the odds, many men think they can have sex outside of marriage and not get caught by a pregnancy. Conception can occur if just one sperm cell is in the right place at the right time. For example, the pre-ejaculate fluid produced by the Cowper's gland (sometimes called pre-cum in slang) can contain sperm cells. Not a large quantity, but it can contain sperm. Hence, it is technically possible for a woman to become pregnant even if a man does not ejaculate within her. This is why withdrawing before ejaculation has a 19% failure rate. In other words, in one year 19 couples out of a hundred will find the woman pregnant when the man manages to successfully withdraw before ejaculating each time they have sex. It could happen the first time -- I personally knew a young man who had it happen to him -- or it could happen after the third or hundredth time.
There seems to be no end to schemes people consider in order to sin while avoiding the consequences of their sin.
"Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God" (I Corinthians 6:9-10).
When you put your penis into a girl to whom you are not married, it is called "fornication." Sex belongs only in marriage where a husband and wife have made a lifetime covenant to each other. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). Withdrawing before ejaculation doesn't change the fact that you will face God's wrath because of your sin.
Pregnancy is the most obvious possible result of fornication. People often take elaborate precautions to avoid it, but for some reason they ignore the other dangers of promiscuous sex. Sex outside of marriage contains a high risk of disease -- some of which are not curable -- because people who engage in sex without demanding a covenant relationship are very likely to have multiple partners. "Whoever commits adultery with a woman lacks understanding; he who does so destroys his own soul. Wounds and dishonor he will get, and his reproach will not be wiped away" (Proverbs 6:32-33). Withdrawing will not limit the spread of disease.
I feel guilty when you pulled Proverbs from the Bible. I realize that I am a super sinner. I am also a Christian, I am a believer in God, but I violated God's word. :'(
The past can't be undone. Yes, you sinned -- that is a fact that cannot be denied or ignored. You can either wallow in self-pity, give up, or change. The choice is yours, but I urge you to change. "Now I rejoice, not that you were made sorry, but that your sorrow led to repentance. For you were made sorry in a godly manner, that you might suffer loss from us in nothing. For godly sorrow produces repentance leading to salvation, not to be regretted; but the sorrow of the world produces death. For observe this very thing, that you sorrowed in a godly manner: What diligence it produced in you, what clearing of yourselves, what indignation, what fear, what vehement desire, what zeal, what vindication! In all things you proved yourselves to be clear in this matter" (II Corinthians 7:9-11).