Missed period negative pregnancy test??

My period is 3 days late, ive taken 3 pregnancy tests in the past 3 days. All different brands, one was an early response test. All came back negative.. I had Nexplanon removed 1 year ago and haven't been on any birth control since then. I already have 1 child so I know it's not that I just can't conceive..unless I just can't now. Not sure if something is wrong with my hormones causing me not to get pregnant, or if it's just not showing up on the test yet? Any thoughts??? What should I do? Do I need to see a doc?