Our bodies seem to change with every pregnancy as well...age also plays a role.
As an adult, it's hard to get in for allergy tests...takes about 2 years on average...and on average, our bodies tend to change from one allergy to another.
I think you need to consult with doctor. Sometimes it happens during pregnancy so in my opinion consult with your doctor.
I don't think anyone has ever puzzled out the food cravings (and food aversions) of pregnancy. I always thought the baby had something to do with it . With the first I could not abide sweet things and the smell of coffee (my favorite beverage) made me want to upchuck. The grown child does not like sweets and dos not drink coffee. My second made me crave sweets. He is now a grown man with a sweet tooth. My third made me gain a lot of weight, which was unusual for my pregnancies. My doctor got upset, but I told him I was very hungry. Number three was the smallest baby I had, so I figured she needed a particular nutrient and I had to eat a lot to give it to her. After her birth I quickly dropped the extra weight.
The baby is a foreign body, isn't it? It's not you or me and it has unique needs. Unfortunately we get sick to our stomachs to supply them. At least that is what I think. And maybe your baby wanted the chocolate, but it was you that was intolerant to it.