Yes, TOM is time of the month, it took me awhile to learn all the lingo here as well.
I find for me personally and I know this varies greatly among women - I have zero gain during TOM. And I have a horrendous period, I have fibroids, so I'm an EXTREMELY heavy bleeder, it lasts for a week and I have debilitating cramps especially in my back, but front as well, probably more then you needed to know. I have checked it out month after month and there is absolutely no difference on the scale for me. So I for one, can't use it as an excuse

. But I have heard that it is quite common for women to gain up to 5 lbs.
Twelve years cancer free? Wow, that's FANTASTIC. Congratulations!!!! You really, truly are an inspiration. I wish you continued good health.
And I definitely agree with those that said, don't sweat the extra 1600 some odd calories. That really is nothing. This IS December, you did great.