im 19 years old, my last period started on april 27 and lasted for 3 days. i have a history of skipped period when i was younger.

somewhere between may 8 , 9 or 10.i had unprotected intercourse, i'm sure he did not came in me, because i saw when he came, it was out.

may 27 came and my period didn't show up, i started to feel my breast may 29, and i got on and off light cramps on june 1. there was no spotting or bleeding. June 3  i used a pregnancy test and came out negative. later that day around 10 and 11 pm my lower back hurt, i made it crack and it went away. the following night (april 4) ,  the lower back pain returned again. and magically disappeared just before i get asleep at around past 12

today( april 5) early in the morning my breast hurt. and had a slight feeling like would vomit  because my tummy is really cold.

all pains go on and off during the day, around 10 am only my left boob hurt. around noon greed veins appeared in my breasts.

ever since i missed my period, i feel like having a normal menstruation,all the pain are only light and felt like my period is about to come any time. still no discharge. i don't feel tired, i don't have mood swings, nor sensitive smells of head aches/dizziness, i don't feel hot as well.

i started my vacation a week before the day of my expected menstruation. i'm under stress because i feel like im going to fail one subject, i also have a balance in school and  i am not sure if i am going to be enrolled this week(this week is our enrollment). i am also stressed at home, and last night(April 4) my sister just gave birth. i m also stressed because of these signs. 

i do exercise , i use the tread mill for a couple of weeks now and i played several set of badminton several days before my expected period.

i don't believe that i am pregnant but given these circumstances is it possible that my period is coming soon? or that i am pregnant..please help