Question about seafood...

So I officially had my last bite of meat till easter. Giving up meat for lent. While also trying to eat healthier. I was on a weight loss journey when I ended up getting sick, having gall bladder removal surgery, and getting pregnant two weeks later 😳. I heard mercury isnt good for you while pregnant, exactly how much seafood I’m i allowed to eat per week to still be on the safe side. I’m not planning to eat seafood every day, most likely about once a week.