I bought another brand called Lady Q. On ebay very cheaply as well. Ive used it for 3 cycles (so far havnt got preggy yet) but i use it in conjunction with checking CM, temping and OPKS. One month my ferning will match up with my CM and OPK results and then another month it wont like this month. Each person is different in how they respond to using it eg TaffyLou gets ferns all the time.
You just have to not eat or drink before hand for hours or else you can get some pretty interesting results on there! LOL

Good Luck and wishing you a short TTC journey