6 days late

So i am 6 days late i keep taking test ranging from first response, ept, and off brand. I will get a negative but 30 min to an hr later their will be a line, i know dosnt cout its a negative, but im not normally this off track on my period. Generally my period is only 2 to 3 days late if all and it would be because of stress or somthing. My cm is very thick and white, usually it is clear and slimy before i start my period, my boobs hurt but only in waves not all the time, extremely fatigue i never take naps and i cant go with out one, more hungry and very moody i know their is no way of know for sure except for going to the doctor which is in a week for me. Im just wobderibg is their a possibility im still pregnant but getting a negative test and if so why am i getting negative test