OPKs?

Lauren • Labor and delivery nurse. Wife. Mama.
Hi all I have been using wofondos for two months now and so far it appears fairly accurate (I get positives when I'm scheduled to) but we have yet to get a BFP. This is cycle # 3. Hoping for a BFP this month. 
​Does anyone have any good or bad experience with these OPKs? Do you recommend them or should i switch brands? I just got them because they were cheap!