What you eat definitely affects your cycle. When I was vegetarian I would regularly go a few months without menstruating, and when I did it would only last a couple of days. Since I started eating meat I'm getting it once a month, for at least 4 days.
Here's an article on how grains affect fertility: 10 Reasons to Avoid Grains and go Gluten Free | Natural Fertility Breakthrough
Your cycle can be a good indicator of your fertility. Here's an article about length of the overall cycle and fertility: Staying Healthy: How menstruation affects fertility
I haven't researched how the length of the menstruating phase relates to fertility, but I imagine that your last period being five days long is definitely a positive thing (and very possibly connected to giving up grains). If this period is late it may be that your cycle is changing (getting longer - apparently a good thing for fertility), or that your body is adjusting.
Personally I wouln't be too concerned but if you are worried you can do a fertility test, or speak to a naturopath or a fertility doctor (I have zero faith in general doctors about these things...!)
Edit: You should also look into the connection between exercise and menstruation. Usually it's said to cause missed periods, but it's not unusual for female endurance athletes to bleed between periods. Neither of those relate to you, but maybe the level of exercise you were engaging in before was regulating your cycle in some way. Lifestyle changes will affect it, and in these cases it's not necessarily related to fertility. Just a thought...
Last edited by YogaBare; 01-02-2013 at 04:58 AM.
"I think the basic anti-aging diet is also the best diet for prevention and treatment of diabetes, scleroderma, and the various "connective tissue diseases." This would emphasize high protein, low unsaturated fats, low iron, and high antioxidant consumption, with a moderate or low starch consumption.
In practice, this means that a major part of the diet should be milk, cheese, eggs, shellfish, fruits and coconut oil, with vitamin E and salt as the safest supplements."
- Ray Peat