13 weeks of pregnancy intrauterine blood, and there is a brown discharge, suggesting signs of preeclampsia, the cause, may be due to the previous blood discharge caused by brown discharge, and secondly, may be the placenta’s anterior state caused by bleeding caused by. 1. 13 weeks of pregnancy intrauterine examination of the accumulation of blood and brown discharge, need to be combined with the previous medical history, such as 13 weeks of pregnancy, if there are symptoms of preeclampsia, it may be the previous accumulation of blood discharged. 2. 13 weeks pregnant with blood in the uterine cavity, and there is no previous symptoms of preeclampsia, then consider now may be placenta previa state or external factors and fetal and other causes of preeclampsia symptoms. If you are pregnant for 13 weeks and have blood in the uterine cavity and brown discharge, if it is the previous blood discharge from the uterine cavity, it is not a big problem, if it is found recently, then you need to do a further examination, it is recommended to try to rest in bed, and then under the guidance of the doctor’s medication to protect the fetus, and pay attention to observation, if you find that the amount of bleeding increased or abdominal pain aggravated, you need to go to the hospital in time to see a doctor.