PCOS and 5 days late

So I was recently diagnosed with PCOS and they put me on metformin a few months ago. I've been tracking my period since then and they've been super regular till now. I was supposed to start Sunday and it's now Friday and nothing. I've taken a few tests and they've been negative. I feel pregnant though. Like I have all the signs I had when I was pregnant with my son almost 4 years ago. Advice???