Hello
thank you for your query.
Such mild brownish discharge/spotting is sometimes common during
pregnancy, but should never be left uninvestigated.
It could be the sign of a low lying placenta, or
internal bleeding within the fetus and placenta.
the only way to be sure is to have an examination by an obstetrician.
For your assurance and the baby's well being, I would advise you to visit the hospital.
Take care.