cramping and brown discharge

LO is turning 3 months Tuesday and I started getting cramps when I pump and Brown discharge. Had some thick cm last week too. I know the cramping is normal early on but thats been gone for a while now. Could AF be working it's way back even though I EB? We aren't using hormonal birth control, and haven't BD for a few days so I doubt that would be the cause. Thanks for your thoughts ladies