Late period or missed period?

Becky
Very confused, hope someone has advice for me...
​I'm currently on CD 46, my cycles are usually all 26-29 days. But all I'm getting are BFNs! Has anyone ever had this and then had a really late or missed period, or waited ages for your BFP?
​Been to my doc (in the uk) and he just told me to wait, wouldn't do a test and def wouldn't do blood test :(
​Thank you for any advice you can give!