My mother had several miscarriages one right after another. It was killing her, both physically and mentally, so the doctor put her on birth control. She conceived me while on birth control and carried me to term. I'm her very much prayed for miracle and that's why I think that medical reasons for using birth control are completely reasonable. I think what gets lost in this whole debate is that God makes miracles every day and you should be open to them.
I personally believe that if you're having sex, you should be willing to have a child and all that comes with it. If you're not willing to have a child, don't have sex! I really would prefer that instead of working so hard on the contraceptive issue, that more pressure be applied to the entertainment industry to get them to stop allowing teenagers (or stars playing teenagers) to have premarital sex at the very least in shows that are targeted to the age group. I'd prefer not living together before marriage. Not all parents closely monitor what their kids do, or have frank discussions about sex. There's a link between contraceptives, premarital sex, and abortions. Sometimes I feel that too much emphasis is put on contraception and abortion, and not enough in addressing pre-marital sex. To me it's important to address the cause of the problem. How a married couple deals with the contraceptive issue is between them and God, and I'm not going to judge. The church provides the guidelines for good decision making.
Thank you Jim for staring this feed and providing the papal encyclias link as now I feel like I can change my answer to Yes, I accept the churches teaching on contraception. It's been something that has bugged me for years.