I was cooking and I used Hot Headz Satan's Revenge hot sauce and ate it. Putting everything that back I used while cooking, I noticed that the sauce's best before date was 31/12/2014. After consumption my stomach feels a little weird, doesn't exactly hurt but feels like there's some pressure so I'm a little worried. (I've been keeping this sauce in the fridge after first use.)

The ingredients are:
Crushed Naga Jolokia Chillies (75%),
water,
salt,
acetic acid,
garlic pulp,
xantham gum (natural stabiliser)

Should I be worried?