hi, some woman may have spotting during pregnancy due to decreased levels of human chorionic gonadotropin, so giving choriomon will fulfill the need, progesterone deficiency can also lead to bleeding, so duphaston may be recommended for that, but four tablets per day is some what high dose, the common side effects are nausea, vomitings, bloating sensation of the abdomen etc, you are under weight to your height, once get examined for anemia which is most common cause of labored breathing in pregnancy, if your doctor suggests you can go for further evaluation. take care.