Seeing as our bodies are more than 60 percent water (with our brains and blood being even higher), I do believe that the increased gravitational pull at new and full moons does have an effect on us. Look at how much it affects such a huge force as the tides - if the tides are pushed and pulled so much, how can our little human bodies not be affected?

Something else to consider is your menstrual cycle. Does your period follow the moon cycles? It could be that your premenstrual time of the month comes right around new moon, compounding the forces already at play. Might be worth tracking.