Am i pregnant or something else?

ok may 28th i had sex and on june 5th and 6th my last period was may 20th my periods last for 4 to 5 days. this month a week before my period my nipples changed color the tip of them turned Purple and the outer part is a little darker then normal. my period was supposed to start on friday the 17th but started the 18th i normally fill a tampon every 2 hours but i only used 4 tampons in 11 hours but my bleeding was light pink at first then brown then the next day it looked like a normal period with blood clots the size of pen tip then i stopped bleeding for 13 hours and now im loosing about a tea spoon every hour. i feel tired sick my head hurts im eating allot at night but not in the day time and After i eat i want to sleep. oh and my first day of bleeding it was a clear mucus mixed in with it. my boobs have gotin wider nipples have grown in size not allot. and i have a cold soar or stress soar idk what it is. but everyone at my work keep asking me if im pregnant cuz of the wy im acting and how my body is changing. i can feel when my period is coming i can always feel it in my back but i didnt feel anything this time and i was bloated a week before i started bloating. so whats going on? could i be pregnant?