Urgh.
So I can be a bit erratic, but my time frame is generally 30-36 days. Longest has been 38. I'm currently at 45 and getting somewhat concerned. I did a test on Saturday which was negative (a v v v v v good thing).
Boobs tender but I swear they just pick random days to do that anyway 
I've got a copper coil which is still where it should be.
I'm a bit stressy in the run up to Christmas but have had far far more stress the past few years and it's never affected my periods. Diet and exercise are the same.
Should I be concerned enough to get it checked out yet or keep plodding on a bit longer and see if it bothers to show up in a few days?