This is our first month TTC. I've been charting and began testing with OPKs every day from day 10 - day 20, but I've gotten a negative result every day.

A few months ago, I had the day 3 hormonal test and all of my levels looked good.

So I'm not sure what to do. Is it possible that because I bought cheap OPKs, they're faulty and giving false negatives? Or should I be using the OPK every single day? My cycle is usually 27-30 days long so I thought I was being safe by testing on days 10 through 20.

I'm brand new at this. Any insight?