Am I pregnant?

everyone around me at the moment is pregnant! im only 17 and have been with my boyfriend for four months. me and my boyfriend are very sexually active, we have sex more or less everyday. I am on the birth control pill but for the past two months have been on antibiotics and have not been using extra protection. last month I was 4 days late on my period then had a 3 day light period, this month I was 2 weeks late on my period and had a 2 day very very light period. nothing major in my life has changed for me not to have irregular periods and I've never had irregular periods before. I have also been experiencing some feelings such as, tiredness, nausea, dizziness trouble sleepin and frequent weeing. im not sure what to do as I've done a HPT and it was negative. do you think I am?

If it says it's negative it is then. You're not pregnant