month late and bfn tests :(

Just don't know what to do, haven't had a period since April 8th 2017, and it's now 6th June.. no period, been brown spotting for 5 days (sorry for tmi) Iv done numberous of pregnancy tests, and had a blood test done last week as went to the docs and they don't understand why I'm late either, my periods have always been around 27-29days.. :( Currently ttc since January and it's very frustrating as I want to keep trying :( x