I'm so confused. Am I pregnant

My period was due on the 25th but it hasn't come and glow keeps changing my period prediction time and when my fertile week was.. Within both fortune weeks I had intervourse both on the predicted ovulated dates.. My first fertile week was the 6-12/1 and now it's saying it was the 13-19/1 either was I had unprotected intervourse and my period isn't coming, I never ever get period signs but this cycle I've had millions of 'pregnancy symptoms, and my nipples are that sore i can't touch them! I tested on the 21st and got a neg, and again yesterday 29th but to me I can't tell it looks like there's a shadow.. I'm unsure of what to do now as my period prediction has changed again! ????? The test shown was the one taken on the 29th with my fmu ??? I'm only 18 and my periods have never ever been late. 
I did have spotting during this cycle as well around the 10-12th!! I don't know what to do.