three weeks late but BFN: when to go to doctors?

[Brodicea]

I have no other symptoms, and last month was very stressful (been signed off for four weeks with anxiety). Also around the time of ovulation I got a handy dose of thrush (grrr), followed by some light bleeding. Am thinking it's probably unlikely, but how long would be reasonable to wait to do to the docs?
I am a bit worried as I got knocked up as a teen and got two false negative pregnancy results, the latter being when I was around 6 weeks....

when i was a teen it was the doctors blood test that told me I was pregnant, but I also had morning sickness by then...

I think if you're 3 weeks late, now is the time! It might just be because of stress stopping ovulation but if the pee sticks didn't help last time, a blood test would be much clearer.

Thanks Faith! Wish me luck

Good luck! (Do you want to be pregnant?)