4 dpo blood on progesterone applicator after laparoscopy?

I am wondering if I can find anyone who has had a similar thing happen and what the results were. I am currently 4 dpo and I also had a laparoscopy for stage 2 endometriosis almost two weeks ago. We tried naturally after the lap this cycle because when I went for my follow up appointment last week, my doctor discovered a nice, mature follicle, so she said this was the best time to try, right after the lap. She prescribed progesterone for after ovulation. I have done the progesterone thing more times than I can count and this is the first time I've ever had any bleeding with it this early. It was just a little bit of blood right on the tip of the applicator. I did bleed for a few days after the lap, but nothing for the past 10 days or so. I'm just wondering if I could have irritated something where the endo was, causing an infection, or if this could possibly be implantation bleeding. I would think it would be too early for that. I haven't had any blood on my panty liner, just a slight bit of light brown CM when I wipe (I know, TMI). Anyone have any experience like this, opinions, educated guesses?? ;) By the way, I'm not positive that I'm 4 dpo, could be 5 or 6. I'm just going by the HCG trigger I did and my RE's timeline.