Should I wear a medical alert bracelet if I have never had anaphylaxis but have shrimp allergy?

Yes. Shrimp allergy is a potentially life threatening allergic reactions to shrimp. The evaluation of food allergy requires a detailed history to confirm the reaction and confirmatory skin test / lab test and possible oral challenges. If one has a history of reacting to shrimp (or any food) and this is confirmed by an allergy evaluation and testing then tx includes: avoidance, Epipen (epinephrine) and medic alert.
Epipen (epinephrine) It is hard to predict if and when you develop anaphylaxis. You can develop it not just eating real shrimp but also other foods cooked even the slightest amount of shrimp or shrimp juice. So it can be adantageous not only wearing a mecial alert bracelet but to carry an Epipen (epinephrine) injection or two with you at all times just in cae you experience anaphylaxis.