Really late bfp?

Did anyone not get a bfp until really late? I'm 11 days late and have taken three tests and all were completely negative. The last one was on Thursday but I'm considering taking one tomorrow morning. 
I've been feeling twinges and as though I've done loads of sit ups for ages now, what the hell is that?!
If it's negative again I'll probably start chugging down parsley tea to hurry my period up, anyone had results with that?