When we are "intamate" with someone, it creates a soul tie. You have bonded yourself with that person. In the physical, you have swapped genetic material that has forever changed you body chemistry. Neither of you will ever be the same as you were before sex.
When one has multiple sex partners, ones soul becomes fractured, as your body was created to bond to only one person for a life time. This is why there is so much mental, and emotional disease in the world today.
One should never have sex just for pleasure, as the sexual act was given to man for the purpose of procreation. That is why abortion, and birth control are wrong. These things are telling God that you know better than He does.
It would be in the best interest of you both to sit down and talk about marrage, as you have already bonded as if you were. If that is not what you think that is what the Lord would have you do, then seek out wise council in deliverance, that the soul tie you have made with her would be broken in the name of Jesus. Niether of you needs to bring that kind of baggage into another relationship.
And go by this rule from now on. If you do not intend to be a husband and father, don't sleep with um.