Confused!!!

Grainne • One toddler princess and another baby princess on the way 👸🏻
Hi all I'm ttc baby #2, I didn't have af at all in November last one was 26/10/15! So I'm 13 days late! My boobs ache, and my nipples are massive, I feel sick (not been sick yet tho), achy back,ribs and tighs! And I've gone mad on cheese! My problem is I've done 4 tests and bfn!! 
I was just wondering how far gone was you when you got the bfp??