I'd trust your doctor's assessment, but it sounds like spotting from ovulation to me (which is fairly normal to experience occasionally). I've experienced it only four or five times in my 35 years of TOM (too few to suspect a particular cause).
It's human nature to draw conclusions based on too little evidence. It's just human nature to see patterns, even when they don't exist. To be confident that you're experiencing a pattern and not coincidence, you have to experiment, keep good records of your experiences and repeat your experiments many times (not just once or twice).
I've read that exercise can increase the odds of mid-month spotting, but haven't experienced that myself. I've not read anything about low-carb doing so.
Low-carbing does affect my periods, but in a positive way. When I eat low-carb, my cramps aren't as severe and my periods seem shorter/lighter. I say seem, because it's not something I record (I have kept records of pain levels and other health symptoms). It's possible that when I'm in more pain, TOM may just seem longer/heavier.
Last edited by kaplods; 01-27-2011 at 10:18 PM.