HELP NEWBIE HERE TTC 1st!! wth is up withOPK tests

ndz2018

Hey everyone! I am 36 and will be 37 next week! My boyfriend and I decided Oct is the month we are going to actively start trying for a little love! I'm very excited and nervous all at the same time.. nervous with the what ifs. What if we have a problem, what if it doesn't happen naturally, will our insurance cover it, etc et OK I'm getting way ahead of myself.
  I have been charting my BBT and doing OPK test(which btw I never seem to get a solid positive) and taking prenatal vitamins. I'm expecting AF next week sometime. I'm pretty sure I O around CD 18/19/20 but again never get a positive OPK test( I tend to drink a lot of water so I'm thinking that may be the problem??)  my cycle can range anywhere from 28-32. 
Does anyone else have an issue with their OPK tests? I use the one with the one line needs to be darker or the same as control line not sure exactly which brand. 
THANKS!! 

ash1980

Hi!  Try the ones with the smiley face - Clearblue Advanced Digital.  You get your high fertility days with the blinking smiley and the your peak day with the solid smiley.  No guessing!  Good luck.  

ndz2018

@ash1980 thank you! Ordered it this morning!