Discharge question

Okay so all day I have been having big clumps of discharge. It's very sticky and comes out in what looks like a really big white blood clot. The last one had a brownish tint to it. Has anyone else experienced this and knows what could be causing it? I'm on antibiotics for a UTI so maybe that had something to do with it? Also I recently stopped taking the pill (about 3 weeks ago) and have been using conforms as birth control instead. If anyone knows what this is please let me know because I have no clue! Never experienced it before.