So confused

My periods have always been regular +/- one day, anyway we have been Ttc for a year and nothing happening. Went to the doctor and been referred for blood tests to have on certain days of my cycle. So I was waiting to come on, AF due last Tuesday. Still haven't come on and am getting bfn. I haven't tested since last Thursday, gonna wait till Wednesday I think and then go back to doctor if still bfn. Really confused, I don't feel that stressed because I know that can affect it. I'm worried there is something wrong with me :( so frustrating xx