Discharge?

I recently had a baby about two months ago. Last week got the Skyla iud. Have had every std check possible and my doctor said everything down there is normal but I've had almost yellow orange discharge & today it was brown. I'm deff not on my period. Sometimes has an odor and I'm just not sure what this is? I have Avery good well known doctor as well. So is this just normal after having a baby? Also I haven't had sex since In like 3-4 months so I'm just not sure what to think. Any ideas?