I'm wondering ..

So I'm supposed to start today and nothing has happened, I've had terrible heartburn for the last two days and I spotted like twice yesterday and I've been extremely tired the last two days . I went to the hospital on December 4th bc of some problems with my chest and did a urine sample and a whole bunch of other stuff and all the tests were normal, should I not test since they didn't tell me I was pregnant when I have a urine sample ? Or would it not have shown then ?