What’s wrong with a few drops of blood in my underwear at 35 weeks pregnant? Is it serious?

If there is just a little bleeding on the underwear at 35 weeks of pregnancy, consider the possibility of preterm labor, but if the bleeding continues to increase, you can’t rule out placenta praevia, placenta previa, and so on. Whether it’s preterm labor or placenta praevia or placenta previa, both have some degree of impact on the mother and child, so both need to be taken seriously in order to avoid an adverse outcome.
35 weeks is not yet full term and normally there will be no bleeding. It is recommended to go to the hospital in time for obstetric ultrasound examination to rule out placenta previa and placenta previa, and once the diagnosis of placenta previa is confirmed, emergency cesarean section is required.
However, if the placental abruption is excluded, and the placenta praevia is considered to be preterm labor with little vaginal bleeding or no obvious abdominal pain, it is recommended to rest in bed and give appropriate treatment to protect the fetus.
Increase nutrition during pregnancy, have regular checkups, count the fetal movements, and consult a doctor if there is any abnormality.