The pattern for mine with my TOM is this: 3-4 days before, I'm starving - all day. The day my TOM begins, it tightens down like a ratchet on overdrive. Stays that way nearly until the end of my TOM. (which is horrible for me, as my TOM is actually a T-O-Three Weeks (every 21 days)) It all evens out in the end, and I typically end up a few days after it's over having lost a couple pounds.
Get a fill. My weightloss didn't fully kick in until I'd had my second one five months after surgery.