Am i pregnant? I have many symptoms.?

Im 18. I live with my bf so we have regularly. I'm on seasonale birth control so my periods are three months apart. In may i had almost 2 weeks of irregular bleeding. My symptoms are nausea, vomiting, headaches, dizziness, urinating more often, more l discharge, mood swings(im a b****, really. lol. one minute im crying the next im screaming then laughing), my hurt and are super sensitive, plus i think they're getting bigger, etc. My job was doing the biggest loser and right in the beginning i dropped 6 lbs like that but now even though im exercising more and eating better im gaining steadily. certain foods i used to love nauseate me and ones i used to hate im hooked on. im gy, bloated, and just don't feel like me. i was also just on 2 z-packs(anti-biotic) about 3-4 weeks ago and am on them usually at least once a month. i took 2 pregnancy tests about 3 weeks ago but they were negative. I was also supposed to have my period this week but skipped it and started a new pack of birth control cause i didnt want extra bloating in the last 2 weeks of biggest loser lol.