Brown vaginal discharge 24 weeks

I just went to the restroom and noticed a quarter sized of brownish pink vaginal discharge. Sorry if it's tmi. I have no cramping or pain. I haven't had sexual intercourse in more than 3 days. The baby is kicking and moving normally. Has anyone else experienced this? I called my ob and the receptionist said they can't discuss medical things over the phone due to their policy. She scheduled me an appointment until Tuesday. She said that if I feel that it's serious go to the ER.