AF is late for the first time ever but BFN are everywhere :(

My last period was January 28, 2015. My hubby and I have been TTC and this past month I decided to start fertility blend. I tracked my ovulation and ovulated the 14th and had spotting then. 
The week my period was due I had very very light spotting feb 23-25. I figured my period was coming early but it stoped the Thursday before it was due. I've been experience nausea and can smell everything now and had nipple soreness which is new for me. I've always had normal periods that came every 28 days. Well February 26 AF was due and to my excitement she was late. Unfortunately though when I took a test the next morning I got a BFN. :(
This past Saturday (2 days late) I had he worst migrane ever. Usually I get bad migranes the day before my period start but now I'm 5 days late and still no period. Headache now past too. 
Today I went to the doctor (found it I had a sinus infection) and took a urine test their and still got a negative. They also took a blood test but I am still waiting the results.
Has anyone expeirened this and found out they were pregnant much later or just got their period late?!?!?! Also if I did have implantation bleeding the 23-25 is it still too early for a home test to show positive? I'm just so confused and feel stupid for even being exited that my period was late :(