Aw mama, totally gets it, paglilihi talaga walang logic, yan ang pinakamahirap part! One of my mum friends with seafood allergy during her pregnancy tried anchovy paste mixed with a tiny bit of vinegar and salt on rice, and it somehow scratched the itch without the full alamang risk, hindi exactly the same but the umami hit helped her cravings. Honestly, you can also try miso paste or even Fish sauce (patis) na very diluted sa sabaw, since sometimes it's the flavor profile na kailangan mo, not necessarily the alamang itself. Might worth asking din your OB if you can do like one very tiny taste just to ease the craving emotionally, walang harm kung controlled lang at walang actual allergic reaction na mangyari, pero ang peace of mind mo during pregnancy super importante para sa baby. Sending you strength, this too shall pass!