You haven't been pregnant, I see...
Suppose, in the future, someone will come up with an incontrovertable proof that abortion, at any stage in the life of the fetus, is murder (excepting when the life of the mother is at stake)... .
Without knowing whether such a proof is possible or not, isn't the safest course of action to assume a pro-life position? If a proof that the pro-life position is wrong appears, the worst that happens is some deaths from illegal abortion, and emotional suffering of women being forced to carry nearly all pregancies to term. If a proof that the pro-life position is right appears, however, millions will have been murdered. In the absence of a clear position, shouldn't we strive to minimize the worst-case scenario?....
Wthether by proof or gradual evolution of values, might abortion be one of those things we look back at with horror, and if the possibility that we might look back at that way exists, should we assume a pro-life position, just to be on the safe side?
Bolding is mine, but I included most of the rest of the post to be clear on context of the statement.
With respect, Sir (or woman who hasn't been there), bearing a child for 40 weeks and then giving birth to it is not just "emotional suffering". It's a life-changing physiological event. Put simply, it is in very slow motion having a chemically active bowling ball put into your abdomen. Almost all of your internal organs are moved, squeezed, stretched, compressed, or develop new blood vessels. The muscles of the abdomen are moved, stretched, changed. The ligaments in the pelvis are stretched. The biochemistry of the nervous system is altered. the digestive system is altered. The size of the vascular system is radically altered, with the accompanying adjustments to blood pressure--a process that rarely goes entirely smoothly. Not uncommonly, varicose veins, including hemorrhoids, develop. The hormonal balance of the body is changed. The back is subjected to stresses without relief for months. The feet and legs have to carry more weight, distributed substantially differently (it is common for women to have to get larger-sized shoes while pregnant, and in some cases, ever after). Psychological changes due to chemical/hormonal changes, quite apart from emotions concerning the process, make the mother-to-be sometimes feel like she is possessed. (This view may be shared by her partner.) Towards the end of the pregnancy, the cartilage of the woman's body alters, allowing her pelvis to expand, and having odd effects on other joints and structures. (I could fold my nose over sideways.) Fluid balance in the tissues is different, frank edema is common.
Let's not forget that the breasts expand and change; that the areolae expand, and the nipples grow-- a permanent change, marking the body forever as having been pregnant, regardless of whether the process continues through birth of a child and nursing. The uterus expands and changes; the cervix changes; if the birth process occurs, the vagina and related structures must be stretched, often tearing (or being cut) to accomodate the skull of the baby. This has a permanent effect on sexual sensation, usually for both partners (loss of the 'firm handshake').
I won't even go through the physical pain involved in labor and delivery, sometimes in spite of medical attention. And, yes, some emotional suffering there too in that it is a level of helplessness usually not experienced without having a stroke. The body is no longer under the control of the mind for hours to (for the very unlucky) days. After the child is delivered, the placenta needs to be expelled as well.
Then there is a whole spate of changes post-partum, even in the tragic circumstances of a stillborn child. The breasts have to either start producing milk, or revert to non-productive status; either way, engorgement occurs, and that is often painful. Hormonal changes are huge. Excess water is excreted by every means, from paroxysmal sweats to frequent urination. The uterus gradually shrinks back; the other internal organs return to something approximating their pre-pregnancy locations. The back, which has been gradually adjusting to the big load up front, is now coping with an abrupt change in posture and weight-distribution. Ah, weight, that's right: Nearly all women who go through a pregnancy gain weight.
Now, let's add in the fact that the mother and father are now legally responsible for providing for the child until it achieves legal majority. That's not "emotional suffering" of the woman, it's cold hard economic reality. As is the risk of being fired for side-effects of pregnancy, like not being able to handle certain chemicals, or offending the boss's sensibilities by not being married while pregnant--or by being pregnant, but then not keeping the baby. Or there may be a need for bedrest to prevent harm to the mother or future child, which has an even bigger impact on employment.
Finally, pregnancy and childbirth can and do kill women, even in America and the rest of the developed world; even with medical intervention. "Gestational diabetes", a pregnancy-related problem with blood sugar levels, is by no means rare; pre-eclampsia, a condition where the woman's blood pressure and other autonomic nervous functions are overstimulated (presumably by the hormones of the placenta, but I believe that is still not entirely proved) puts the woman at risk of hemorrhage, liver damage or stroke; eclampsia, where the dysfunction caused by the pregnancy does reach the level of major medical problems, kills more women in the developed world than any birth-related issue. (Pre-eclampsia is so dangerous that a woman will be 'induced' to begin labor early, even if it means the child will have to be in NeoNatal ICU.) Postpartum infections can be lethal, painful, or cause sterility.
If you're going to try to base your argument on "what's the greater harm", you should not posit that there will be nothing more than some "emotional suffering" involved in unplanned /unwanted pregnancies.
Added: Please note that I have limited the above discussion to just what happens due to pregnancy and delivery. If the child is nursed, cared for, etc. there is a whole new category of physical and hormonal issues. Then there's the impact on the siblings (if any) the partner (if any) and the public (if the mother cannot or will not provide for the child). For at minimum 18 years. And that's with a healthy child!