My period ended on 7th of September this month & I had u protected sex on the 8th and on the 16th the day before ovulation and today on the 21st I went to the bathroom and in my underwear and on the tissue there's brown/pinkish discharge? It's only very small amount and I'm not sure if it's implantation bleeding but if not I don't understand why I would be having brown/pink discharge at this time in my cycle any advice would great.