not allowed to eat crab while pregnant

I was eating crab every few weeks while pregnant with my first born. she's a healthy 12yo now. hyperactive? not at all. my second born, however, Idk why but I abide by the rules avoiding all things they say I should avoid, and he came out hyperactive. he's 10 now, still hyperactive with adhd. so I figured, if it's gonna happen, it's gonna happen. we can only take so much precaution. I think as long as there's a healthy balance, it should be fine. I did, however, ignore a craving with my firstborn. wanted kfc so bad but was told to avoid fried chickens. my baby came out salivating. like seriously it was always dripping. so my husband bought kfc and gave her a lick and I swear, it stopped. I rly think u should have some crab. just balance it out after. also, I know it's hard but try to block all these noises. It affects the baby greatly.