SMEP and OPKs

Kat
Hi Ladies,
​This is our fourth cycle TTC#2. AF just showed up two days early. Boo!! We conceived right away with #1 (almost 2 yrs). 
​Thinking that we should try SMEP this month. 
​Who has tried / what was your experience and what is the best OPKs to use? I definitely don't want to break the bank!
​Thanks!!!  :-)