what is going onnnnn.

okay so i was supposed to start my period friday july 18th. my last period was june 20th/24th. i am literally a week late. i have pms symptoms. my boobs have been hurting, moody, tired, cramping on & off. i have take 4 pregnancy tests. they were all negative. i don’t know why my period hasn’t started. i’m only 18. & i have no one to talk to about this kind of stuff. i don’t know what to do. my cervix is low. & it feels firm. i’ve been having discharge. creamy/white. & watery/clear. i’m so confused.