20 days late

My cycles have always been 30-35 days long.. I started trying for a baby this month and now im 20 days late.. CD 50.. and i have been getting all negative pregnancy tests... Ive tested 4 times.. The tests dont even show so much as a dye run. Its one pure line.. Ive talked to my doctor and she checked my thyroid and its fully functional and working, everything within normal ranges. I also got my first UTI in my 20 years of living last week which I thought forsure meant pregnancy. What would be the next step? Anyone else experience this and come out with a BFP? I wasn't expecting to get it on the first try but this is very coincidental.