could use some advice!

L.
My period is 2weeks late and I've taken several pregnancy tests and they all say negative. 
I had sex and my bf didn't cum inside me. 
Is it likely that I'm stressing myself out and causing my period not to come? 
**Update**
My period is now 19 days late, tests are still negative and I had one day of cramping and spotting. This is driving me crazy!!!