Pain in LI4 followed by a miscarriage

First, I am sorry to hear about your miscarriage. To put your mind at ease, however, I can assure you that you -did not- cause, contribute or in any way modulate your miscarriage by using acupressure on LI 4. Not to discount the emotional aspects of miscarriage, which are significant, but it will happen naturally by the body if it terms that the fetus is unhealthy. While there are women who are prone to miscarry, and Chinese Medicine has good diagnostic and treatment tools for this, this is likely not your case. And even if you were prone to this using some mild acupressure on that point would not likely change much. In other words, you miscarried because your body thought that was the right thing to do, and not for any other reason.

While there are contraindicated points, they can and still are used by practitioners throughout pregnancy for any number of reasons without issue (with proper training of course). When we do labor induction with acupuncture the stimulation on the points is strong and we use multiple "contraindicated" points.