Hi and welcome, trishalishous. If you've got to deal with infertility, at least you'll be in good company here...

1MP, I was told to drink 3L of water per day and increase protein from start of stims. My concern with mineral water is that it contains mineral salts and I don't know if that would cause problems or not. Probably best to ask your FS about it. You can drink things like coconut water and gatorade (or similar) as part of the 3L, but I stuck with plain water. And, yeah, I had to go to the toilet a lot...

CatyO, Lucrin is mostly used the same way as Synarel, but if you haven't used it for suppression it can also be used as a trigger (as can Synarel). The reason for using Lucrin (or Synarel) is to reduce the risk of OHSS. The down-side of it is that it can cause issues with your lining so you may not be able to do a fresh transfer (not sure if that's always the case or just sometimes?). I'd imagine they'll make a decision once they see how you respond to the Puregon.