Could I be pregnant?! please answer! any advice?

Sierra
Okay so me and my boyfriend have been trying to have a baby. This would be my second child.
My period started on November 27th and ended December 1st. My tracking app said I was fertile around the 8th of December. (((My periods can be irregular btw))). So we had unprotected sex on December 6, 8, 11 and 12... I've been having symptoms of pregnancy (breast tenderness, cramping, nausea, and VERY tired)(which isn't really like me). I took a test this morning (18th) and it was negative . Is it too soon to show up On a test ?? I should be getting my period in about 4 days. 
Any tips ? 
Thanks😁