Hi, I missed two contraceptive pills about the 7th and 8th of June. Had unprotected sex on the sunday before (so the 4th of June). Had withdrawal bleeding for about 6 days which stopped 4 days ago. I was told it would be unlikely that I would get pregnant seeing as I made the pills up and had withdrawal bleeding. However am now having a small amount of pinkish brown spotting on and off since yesterday (only just enough to mark my underwear and noticeable on toilet paper. Its been almost two weeks since I had unprotected sex. Is this bleeding just leftover from the withdrawal bleed/period or could it be implantation bleeding?