Yuri, I would say my biological child and my adopted or chosen child, but only if it was important to make that distinction. Normally, none of us should care. They are both/all your children and I would assumed equally wanted and loved.
Natural works but might lead to your other child to beg the question, "Am I unnatural?" Blood child might possibly be used in another place, but not in North America by English-speakers.
Sometimes people want information. That's fine, but we are under no obligation to assuage their curiosity. If the doctor needs to know, or a child is having a problem that makes telling the school the situation, then 'step-child' or adopted child is still the way to discuss or label them.
A stepchild is a child from your spouse's former union whom you have not adopted. If you adopt them, they are your child and all the adoptive words would apply
I think love interests or romantic interests could work, given OP's latest context.
From tvtropes.org,
Love Interest
The princess to be rescued, or the Prince Charming to sweep the heroine off her feet. Or just someone that happens to become romantically involved.
It's a Super Trope so universal, that there are too many specific examples to list. There are a few in the list below.
The list includes Girl Next Door, Girl of My Dreams, and Hello, Nurse!.
When applied to real life, I think love interest is just as flexible. A love interest is basically a person that you are romantically interested in. This could range from something small, like going on a few dates, to something big, like love and marriage.
A romantic interest is similar to a love interest, with the possible nuance that a romantic interest concerns more casual relationships.
I wasn't able to find any reputable dictionary sources, so I imagine that the definitions vary from one person's opinion to another. However, if you call these girls your love interests, I think people will get the point that you are interested in them romantically or that you pursuing them romantically to some degree as described above.
By the way, you could also say that you are interested in these girls, or into them. They mean that you have a some kind of romantic interest in them, though it suggests a casual one. I don't think it would include "loving" someone, unless it's unrequited love.
Best Answer
You would not normally use the term "carry a pregnancy" in everyday English. It is very common to hear the phrase "to carry a child" or "to carry child". The example you cited appears to be a technical definition that uses the more formal medical language "to carry a pregnancy", but again you would generally not use this phrase in everyday writing or speech.
Other common ways of referring to a pregnancy: