Concerning or not???

Kristin

I'm 28 days late. I have been trying for a baby but i took 3 tests that all read negative. Late last night i started light bleeding. This morning woke up to dark heavy with blood clot size of a quarter.. Should i be concerned? Could i be pregnant and this be bad or could this just be a late/missed period? I'm on vacation so I'm not close to my normal doctor and dont want to go to the ER unless needed...