Hello dr i had 3 embryo transferred on wednesday and friday i had a brown discharge with a lower back and abdominal pain is this normal?

No: It is extremely rare to have a day 3 embryo transfer anymore. Most likely there was an issue with embryo quality. When that occurs the hormones are more likely to drop and be low and that can sometimes lead to spotting, bleeding, or discharge. It would not cause pain. Sometimes that if from the ovaries and usually goes away quickly. If it persists i would call your doctor.