Original vs. Reissued Birth Certificate?

i know with my own birth certificates..there are three of them....two from before my adoption...one with 1970 and one with the year 1971 ...the one after my adoption is 1970..they have no clue when i was born they arent even sure my birthday is right..nor any of my siblings...i do know when i got my first pport when i was going overseas with my husband in 1990 he is in the military..it took six months to get it....i have often wondered if its because i was adopted...noone else then took that long...but i do know from talking to the adoption agency for the state of ky...my birth certificates all three of them are tied together...because she is how i found out about having two before the adoption one..