Midcycle spotting after miscarriage?!

I had a miscarriage at the end of march. My first cycle post miscarriage was fairly normal. Second cycle seemed normal, but had a couple days of light spotting about 5 DPO (thought it may be implantation) then got AF right on schedule. Now I am on cycle day 10 and have very light spotting again! It started the day after my first acupuncture session (coincidence possibly?!) I usually don't ovulate until about day 18. I have never had spotting midcycle in my life until now. Any ideas??