If the patient usually has regular menstruation and this period has very little bleeding, it may be related to pregnancy. This is because pregnancy can cause this small amount of vaginal bleeding if it is followed by a pre-eclampsia or ectopic pregnancy. This is because, in the case of intrauterine pregnancy with pre-eclampsia, it means that the patient has factors that affect the development of the embryo or that the embryo itself is not developing well, with low levels of HCG and progesterone. In the case of ectopic pregnancy, the activity of the gestational sac is usually bad and the HCG and progesterone levels are very low. This can lead to a small amount of endometrial bleeding in the uterine cavity or bleeding due to separation of the embryonic tissue from the normal uterine wall. In this case, the patient is often accompanied by early pregnancy reactions such as breast tenderness, nausea and vomiting, and the diagnosis can be clarified by checking blood or urine HCG.