Well I have my period right now and just restarted Induction, and I'm really not that concerned about it. To be honest, I usually weigh a bit more than usual during my period, then I go back down afterwards. I figure that since I'm eating better in addition, I will in fact have greater weight difference than expected and it will make me feel good and help me continue to eat low carb. So basically, I think it's good to start when you have your period, even if it only makes you feel like you lost a lot of weight. Good luck!