16days late.... Negative Tests

Faith
I am 16days late on cycle day 46. I took 3 tests on days, 3,5,&12 all of which was negative. Is there still a chance? I am so confused. I haven't really been stressed of changed anything about life so nothing makes since. I have been so nauseous, heartburn like crazy, & odd cramps. All the same as the first time I was pregnant but miscarried right before 6 weeks.