pregnant or just stress

My period was messed up last time with me bleeding twice  in September. I've been taking birth control for six years, I did switch about 4  or  so  months ago to a lower dose estrogen kind.    
    
 
 
 Anyways I've been in a long term 
 Realationship for About 1 and a half years. When I say we have sex we have sex, 5-6 Times on the course of two days sometimes. He ALMOST always cums inside of me. Sometimes even continuing with him, and his cum still inside of me to bring me to edge again. Anyways my period is late, I have been stressed. I took a test this morning and it was negative. Was three days too early? I  don't get sugar pills with this pack. It's a 22 day. I'm pretty sure it's just stress unless I'm that 1% or is it possible it's late cuz I had two periods last month?