42 days late

Hi, hoping someone can help.

its been 42 days since my last period, i have done a few HPT including one today and had a blood test at 28 days late which was all bfn. 

The last few days I have been really crampy and have very bad lower back pain. My ovaries kind of ache. Also had some brown/pink discharge when I wipe(tmi sorry)! 

I am just ovulating now or could it be something else. Not had this before or with any other pregnancy. Bloods normal.