Thoughts?

My cycles last 28 days. I'm on the pill and haven't missed any or had to double up. My last period was May 11th and ended on the 15th. I started my new pill pack on the 15th and had protected sex on the 17th which was cycle day 7. For the last two days when I wipe I've seen light brown. The first time I notice was after a bowel movement (sorry tmi) and it was light brown mucus like. Today after another bowel movement it was brown with possibly slight red. It was kinda hard to tell. I have had some spotting similar to this mid cycle before, about month before last. Anyway, we are not TTC and I'm a big worry wart. I was just wondering if anyone else has had something similar happen?