white spot in toilet??

I've been on birth control for 3 months. I take my pill everyday at 7am and I noticed a few minutes ago (its now 6pm) that I had a little pea sized white dot in the toilet when I went #2. tmi..it wasn't attached to the stool..it was just floating in there (no it wasn't in there before I sat down). it's been almost 12 hours since I took my pill so o don't think it would be that.. has anyone experienced this before?