Am I pregnant?

I had the nexplanon implant for 3 years in my arm. Got it removed DEC. 14, 2016. I didn't have a period those 3 years. As of today, I have sore, tender, and larger breasts, light discharge. Runny nose, cramping, legs falling asleep a lot. Today I've just srtard having a metallic taste in my mouth, but dry mouth for a few days. Took a pregnancy test this morning, it was super negative. I'm wondering, if I don't know when my periods are supposed to be, how do I know when I can test if I already have these symptoms. I've had unprotected sex all of December. A blood test was done last Friday, also negative. But my boobs and metallic taste didn't Start until this week. Thank you in advance.