Adv dig OPK HELP please


I got a positive smiley face on adv digital clear blue on Friday cycle day 12 (I have gotten 2 negatives prior days) So I thought it was legit. I have another pack so I used the new one today 6 days later and it's a positive solid smiley face. ( I tested the last three days and it was negative) Idk what is going on. today is cycle day 18.