Late period but still BFN.. any stories?

Rose
Expected a.f. start date December 31st. Predicted ovulation window December 12th through the 18th. Only day we BD during that time was December 15th. Tested with first morning urine on Dec 30th and Jan 1st with Walmart 0.88 cent tests. Both BFN. Still no a.f. so I tested again today (4th) around 9pm with an e.p.t. and still a BFN.. Anyone else ever experience this and eventually get a BFP? I'm going to test again in the morning with my first morning urine just in case that was the issue but I'm starting to lose hope.. TTC for many years already with one miscarriage Oct 2013 :(