Yes, it’s possible. Speak to your pastor about the details.
The question you should be asking yourself though is this: Why do I want to marry in the Church? Is it because you are a believing, practicing Catholic who is called to the vocation of marriage, which forms the couple in sanctity and helps them to raise their children to be saints? Or is it because you were brought up Catholic, have found a nice guy, want to make your romantic relationship with him “legal,” and figure that the best place to do it is in the local parish church?
I ask this because the circumstances you’ve shared suggest that you have not taken seriously the Church’s teachings in the past and may not be considering taking them seriously in the future. After all, you already have one child born outside of marriage and have been involved in an unchaste relationship with your fiance that has resulted in a second pregnancy. If you are not serious about living right now the life of chastity the Church expects of a single person, how will you be prepared to live later the life of chastity the Church expects of a married person? (All are called to chastity. For married people that means fidelity to their spouse until death them do part.)
If you want to marry as a Catholic because you believe in Jesus Christ and take seriously the obligation to be obedient to the Church that he founded, then I urge you to use this engagement period to seriously study your Catholic faith and prepare to live as a devout Catholic married in the Church. If you are not serious about your Catholic faith, perhaps you should seriously examine why you want to be a Catholic and be married in the Church.
My prayers are with you and your family. God bless.
