We'll see what it mean when you stop for a while. I would put on another area after you stop and see if it swells. Your stomach area is very sensitive to allergy. When you have a reaction it's typically the first place you get hives. Try some on your inner forearms for a couple days. If you're allergic just get a refund and try something else.
In 4 years only 5 or 6 people were allergic to Yohimburn. It's usually the aloe or the peppermint.