Alright, so you are pretty much saying life starts at conception. Technologically, you're right. At conception a new cell is created out of two old and pre-existing cell. A zygote is a cell, a cell is alive, and that is simple biology. The problem is, no one in our society fights for cell's right. We don't consider killing a cell immoral or bad. We place different value on different life forms, mostly going by their intelligence. We swat a fly because killing a bug isn't murder. No one in protesting and rioting over the sale of bug spray. Once we get into being with higher intelligence, such as cats, dogs, horses, cows, monkeys, and apes, then we see protest to them being treated inhumanely. There is a direct correlation between the value of life we give an organism, and it's intelligence, with several exceptions. I am not speaking for myself so much as general society, so don't bring in mentally handicapped people into this. I don't make our society's general feelings about the importance of life.
Now, I'm applying this to abortion. A fetus within the first trimester doesn't have significant brain activity. Granted, it's no longer just a cell, but it's not an intelligent being either. It's somewhere in the middle. Around the area of a sea slug. As mentioned before, no one cares about the death of a sea slug. I imagine that you'll go back to that it'll grow into a full being. The problem is, it's not now. We can get a lot of things to grow into human beings, but we don't.
And in regards to condoms Vs. abortions, by point was I don't consider a sperm/egg cell to be anymore human than a zygote. Thus, to kill a sperm cell is no more morally wrong to me than to kill a zygote.