
I'm sorry about your BFN.
First let me say that going off of BCP can affect your cycles for 4 cycles. Not months, but full cycles. They could be shorter, longer, annovulatory, extra fertile, etc. with no two cycles alike. Even after 4 it may take awhile for your body to return to its true norm.
As far as spotting goes it's perfectly normal to spot before your period. Some women also commonly have spotting around ovulation or in the middle of their luteal phase for no apparent reason. It's just one of the joys of being a woman.
With your concerns there are a few things I would try. First I would begin to use OPKs and highly recommend charting your BBT. That can let you know a great deal about your cycle and help you put together questions for other women or your doctor. After that if you haven't gotten pregnant you should ask your doctor to run blood work on CDs 3 and 21 to check your hormone levels. Estrogen, LH, FSH, prolactin, progesterone, etc. You could also request an ultrasound to make sure your ovaries look good.
Just take it step by step and day by day until you have some answers or a BFP.
Good luck!