Almond milk causing stomach cramps

I’ve been vegan for about 10 months, and I consume almond milk almost every day. This morning, soon after the shake I had for breakfast, I got medium-severe stomach cramps that partially subsided but stuck with me mildly all day. Not feeling well in the evening, and feeling a bit lazy, I decided to have a bowl of granola with almond milk. The cramps returned in a big way. The interesting thing is almond milk is the constant during both meals, but they were different milks. The one I had in the shake was Silk chocolate, and the cereal had 365 organic unsweetened vanilla.

Does this have any legs? Would I develop some kind of allergy or intolerance after nearly a year?