Pregnant?

So my husband and I have been trying since the beginning of December. I got my mirena out november 29, and I started getting periods again in January and they have all been pretty regular. Anyways, I'm 2 weeks late, and took a pregnancy test last week and it said negative. It was a cheap off brand test, but I was wondering if anyone thinks there is still a chance I could be pregnant? I am tired more than usual,(even my boss has noticed) and my face has broken out worse than ever before, and I have noticed more discharge, but I was wondering what you guys think? And if it's just all in my head, or if there is an actual possibility. I do have a GYN app on the 28th but I'm anxious.