No period

according to this app I am 5 days late for my period,according to the other tracker app I am 3 days late. I am worried. I have done a test this morni g that was negative. I have the copper coil but the last few times I have had sex with my bf it hurt when he went too deep (sorry if tmi). I tried to check if the coil is still in and it is, but I'm not sure if the strings are shorter or longer. does anyone have any suggestions? should I go to the doctor?