OPK - Surge or No?

My husband and I have been ttc for almost 2 years with 2 ectopic and 1 miscarriage. After rounds of tests and procedures, fertility doc has cleared us to try naturally! He advised us to use OPK but since this is my first cycle I'm not 100% sure of what I'm looking for. None of the tests appear to be as dark as they should be. Am I overthinking? Or does the 3rd test look like the winner?