You can always test early -- just know that you might get a bfn before a bfp! I personally like to catch the squinters. :) No, there's no way to tell if it's sticky, and the bloodwork only tells if all is growing well at that moment -- something might always go wrong later on. :(
UTI? Hate those! Tell your PCP or OB that you might be pg and they'll give you antibiotics that are safe during pregnancy.