Pregnant..yes? No? Maybe? Idk!!

My periods almost always come close to the same time every month. For example, I got it November 25th, December 25th, January 19th, & February 17th. But, I haven't gotten it this month, nor have I even had cramps or any signs of it coming. I took a pregnancy test a couple days ago, & another one today. Both were negative. Where's my period?!