Pregnancy symptoms

Miranda • I am taken since January 19,2012. Been trying to have a baby since Oct. 2015. I am 19 years old my boyfriend is 23
I am currently 19 and TTC. It's been a week and a half since me and my boyfriend had unprotected sex. For the past week or so I've been having Pregnancy symptoms. However, when I took a test today it was negative. Can someone please tell me what was wrong. On Monday the 13th would be exactly 2 weeks since the unprotected sex. Can soomeone tell me why I am experiencing the symptoms and having negative tests.