Bleeding on the 45th day of pregnancy is not normal. If the pregnancy is confirmed to be intrauterine by ultrasound, if the gestational sac does not yet have a fetal heart or bud and there is a small amount of bleeding, you need to take good rest and pay attention to the preservation of the pregnancy. If the gestational sac is regular and there is still bleeding, you need to use oral progesterone or intramuscular progesterone to protect the fetus. If the gestational sac is regular and still bleeding, you need to take oral progesterone or intramuscular progesterone to protect the fetus. If the fetal heartbeat and fetal bud are growing well and there is still a small amount of bleeding, you should also rule out cervical lesions to see if there are any cervical polyps.