I'm expecting some of you to say/think I'm mad but before you do - I read Rebecca Fett's It Starts With The Egg before TTC and Brain Health from Birth post conception and have taken most (not all suggestions) on board. I'm not totally convinced on some of the points but some are reasonably robustly supported by research.
As per recommendation I used a water filter before conceiving and at beginning of first trimester and then I was so sick and exhausted I didn't sort it out and have been drinking unfiltered tap water ever since.
I'm sure though this is fairly normal in UK, isn't it?