Congratulations on going the 13 hours of fasting. Next you may be able to go 14 hours. I have found that when I get hungry if I can get through a few minutes or a half hour most of the time the hunger will fade for a while. Maybe having some water might placate you for a little while. Did you say the other day that you weighed after drinking water? What would be the purpose of that? I think it's normal to gain weight with your period, I did.