AF is 4 days late but HPT is negative

Amy
I am 4 days late for AF but I keep testing and getting a negative result! What are the chances that I can be pregnant? The HPT says its 99% accurate but I see on baby blogs that some people take days or even a couple weeks past a missed period to show a positive HPT??? Do I sti have a chance this month? I'm 36, TTC our 1st.  I don't have period cramps like I normally do and My cycle is usually pretty spot on. I'm praying this is the month for us!! Has anyone else had a similar experience and ended up being pregnant?