Hi rachypoo,
I understand your pain. The same thing happened to me last month, af did turn up 10 days late! Checked on the internet for others at the time who were late, some had done hpt and BFN, some af turned up and some were very late and BFN but got a BFP when 8-10 weeks pregnant! all very weird and annoying. Then I found some people who had periods as usual but were pregnant! The thing is, where do you actually stop yourself thinking that you may be pregnant and just not know it yet? I hope this is your month sending millions of baby dust your way, hang in there, when was your last hpt? Leave it a few more days and if no af and still BFN, go to your dr. Then again , a few girls got BFN with a blood teat and were pregnant!!!!!!!! It's never ending.
Take care
Bev x x