Adopting

SABRINA
We have been trying over a year now and haven't prevented getting pregnant for 4 years. We've been tested some but insurance doesn't cover infertility test so we stopped testing due to $1400 medical bills in one month. 
When should we start to look at other options? IE adopting or IVF.
Has anyone adopted? How was the process and has the placement been successful? 
Thanks to all for any advice.