pregnant?

Hi everyone! So here's my situation.. I was on the pill for about 4 years, until about a month ago. I got sick of forgetting to take it all the time so I just stopped all together and got my period Nov 15. I went to the dr on Dec 2 and she prescribed me the patch. I've been waiting to start it until I got my next period. In the meantime my boyfriend and I have still been sexually active. My period is now 13 days late.. I took a test a few days ago and it was negative. Can anyone give me tips or advice to help calm my nerves?! Side note: I also started taking xanax as needed Dailey for GAD, could that have anything to do with it? Thanks!!