I'm really sorry to hear about the loss of your pregnancy in December.
I would say that since you had a negative pregnancy test yesterday, you're experiencing menstrual symptoms and the spotting is likely just the start of your period, not indicative of a miscarriage at all.
It's so tricky to decipher early pregnancy symptoms from PMS, that's for sure, but in your case, it sounds like your cravings, heightened sense of smell and breast pain can all be attributed to premenstrual symptoms. I experience all of those symptoms myself in the week to week and a half leading up to my period. That's because there's a rise in hormones before our period that's similar to the increase in hormones experienced in early pregnancy.
In short, no, I don't think you're experiencing a miscarriage, and I don't think that you're pregnant this month.