Ah alam ko yan, girl! Yung brownish discharge while using Neo Penotran is usually normal, it's the medication working and helping clear out the infection, kaya don't worry too much. A few of us tried it din for vaginitis, at lahat kami may similar discharge in the first few days, so you're not alone. The important thing is na you complete the full 3-day course kahit makita mo yan, kasi that's how it gets rid of the bacteria properly.
That said, if the discharge gets really heavy, mas maamis ang smell, or you're feeling extra pain or itch, better to message your doctor or OB just to be sure everything's on track, every body reacts slightly different din. You're doing great taking care of it!