help i am so confused

Vianey
Can some one help me out supposedly am turning 28 weeks tomorrow which is 7 months right? Well when i went to my first appt the told me i was 8 weeks & 5 days and that my due date was june 18 . Well idk how that works if am turning 28 weeks = 7 months its throwing me off because i am suppose to have my baby shower may 20 
Can some one help me i am really confused i have an appt til next monday but its makin me worry that i wont be due june i would be due in may could it be that the docters are off . I didnt get my period on October 2016 my first appt was November 11 2016 i was told 8 weeks 5 days but now i dont know what to think