If I have already had premarital sex with my boyfriend, can we still get engaged and married?
Yes, and that is exactly what you need to do, as soon as possible, even though you have already committed a terrible sin and will have to suffer the consequences. But, before you get engaged, you need to repent of your sins, asking for forgiveness from God as well as confessing your sin to your parents, against whom you have also sinned. Then you need to have an engagement meeting where you parents will come and meet you and the pastor of the church to see if there are any other “things” that may hinder you from getting married. If everyone is in agreement then you need to begin planning the wedding. The wedding will not be as beautiful as it could have been if you had not sinned the way that you did, if you would have kept yourselves pure. You need to have the religious ceremony so that you enter into covenant before God and witnesses. You need to do this quickly so that you will not continue to sin against God by participating in premarital sex.
There is another thing that I would like to share with you. The fact that you have already had premarital sex does not obligate you to get married, especially if your man is against the teachings of the Word of God, or, if he is not a faithful man in whom you can trust.
Even if you choose not to marry, you still need to repent of your sin and confess your sins. You also need to stop having premarital sex. Your boyfriend may even try to get you to sleep with him today. If he does, tell him about your firm decision and let him know that he needs to repent as well. If he agrees and wants to start a family with you then you should so that after you are married, you can live a pleasing life to the Lord. If he truly loves you then he will quickly put forth effort to get engaged and married but if he decides to leave you then you will know for sure what kind of man he is and quickly realize that he was using you. May the Lord give you wisdom to live for Him and do what He wants from this day forward.