Hi! Brown discharge while on Diane pills can happen, a few of us in my circle experienced it too, usually towards the end of the pack or when the hormones are shifting, kaya don't panic muna. But honestly, since your last period was Dec 22 and it's been a while, mas better na you check with your OB para sigurado, especially if this is new for you or if there's anything else going on, they can give you the real answer based sa history mo and how regular ka usually. The Diane pills can cause spotting or brown discharge talaga, pero better safe than sorry pag something feels off, you know?