where's my period?

I am now over two months late and I have taken multiple tests all bfn. I have been to the doctor n had a blood test for hormone imbalance awaiting results. but my question is how long do I now wait until I start badgering the doctor again ? I mean I don't feel pregnant and I have been pregnant 3 times before. I've had mild craning on and off since before I missed the first period and loads of spots. but that's it other than a strong metallic taste in my mouth twice two weeks ago. the only thing that's changed is yesterday my boob's are a little tender which has never been a pregnancy symptom for me but that could mean my periods two weeks away. I am massively fed up has anyone else experienced this and gone on to have normal periods ? I'm 30 BTW and came off merina coil 7 months ago