pregnant? or period late ?

So my period has been irregular because I was on depo a few years ago I did get them every month before me and my bf started dating we have been together since February  any way I recently started taking prenatal vitimans they also made me moody witch I think is normal? I was supposed to start my period 4 days ago I have been feeling symptoms that is similar to my period but also similar to being pregnant my boobs are hurting but not to bad my nipples are getting darker I have this white milky discharge  at least 3 times a day I have sharp pains shooting through my back and stomach sometimes they feel really bad  sometimes I feel like something is kicking me lightly today I just noticed that my labia has gotten smaller and darker  I really don't know what that means but. I'm kinda scared my stomach gets. Bloated and I just feel randomly like I'm gonna throw up I have taken multiple pregnancie tests and they always come back negitive I never took one first thing in the morning but I read on the back that it's highly recommend  has anyone else felt this wy is this something serious ??? I haven't felt sick the whole time just tonight and a couple nights ago I am so concerned. I'm thinking about going to the hospital could something  be wrong with me or am I just freaking out someone please help preferably of you was pregnant before please !!!