Doctors don't have a plan for this because it's not a disease. It's due to normal hormonal changes that occur right before and during menstruation. Emphasis on normal changes (although these can be quite uncomfortable.)
Thus the "treatment" is to address the symptoms rather than a cure (well, perhaps entering menopause may help, although menopause can bring some interesting symptoms itself).
I have worked with some nurses who, because of their work schedule, have some terrible eating habits, loading themselves up on caffeine to keep going, skipping meals and never getting sustained (i.e., 20 minutes each day) exercise. Some did find reducing the caffeine in their diet, switching to more complex carbohydrates, and including some aerobic type exercise (usually walking or stationary bike riding as these two things were easiest for them) for a SUSTAINED period of 20 minutes at least five times a week seemed to help greatly with at least some of these symptoms...especially the emotional highs and lows.
The idea of being of this injection is to prevent ovulation which, in turn, avoids pregnancy. Therefore, if you are not having menstrual periods, you are not ovulating and pregnancy is not an issue.
Pregnancy tests do not check for estrogen. Pregnancy tests check for a specific hormone that is released when implantation occurs that has nothing to do with estrogen.
There was, at one time, a long posting going on here from women who were experiencing movements in their stomach yet were not pregnant. This is not unusual and might often be caused by food, liquids and/or gas moving through the small intestine (remember you've got at least 20 feet of small intestine in the human body). In addition, one would not feel fetal movement early in a pregnancy; it is typically not until many weeks into the pregnancy before this starts.