Ovulation test help!

Me and my fiancé have been trying to get pregnant since about January. Taking prenatals, using preseed, soft cups, have a known donor that helps very often. 
  We had taken a break, starting back decided we'd go ahead and buy the clear blue digital tests. I've been testing for a week and I still haven't gotten anything but low. I'm starting to think maybe there's something wrong with me? Idk I just would like to hear if anyone else had similar experience with these tests and if I should be worried or could be trying something different.