I guess we'll have to disagree, but your posting history suggests you are not truly in favour of both premarital sex and abortion as virtues, and that you are merely taking these positions now because you've talked yourself into a corner.
I think I have pretty clearly been in favor of abortions.
As for premarital sex. The real problem is that premarital sex is a very broad category.
There are certainly forms of premarital sex I would find distasteful (which you are free to read as immoral). But not all. And whether or not a condom is used is not how would determine its morality.
The real issue there is that the choice to engage in premarital sex does not really intrude on me, whereas the choice not to abort a child you cannot afford does.
I do not believe a fetus is a person. And even if a fetus was a person, failing to bring an unviable fetus to term is not murder.
I do not believe that abortion should be legal once a fetus is viable though.
Then based on your only just stated beliefs a fetus (at least before viability) is just a bunch of unwanted cells. It is no different than say a rotting tooth. How then would abortion be immoral?