clearblue advanced digital opk false positive??

I've been using the advanced digital OPKs. They worked wonderfully and I got a BFP my first cycle using them!!  Unfortunately I had a MMC and a D&C in November. This is my first cycle back again. I started testing CD7 and ended up with a positive on day 10 but nothing else (I was using the clearblue monitor and cheapie strips too). I realized that it as an old holder and so I started using another one the next day. I've had a long cycle after the miscarriage so I decided to just keep testing until I get a solid smiley or my period. This is CD24 and I've had 12 days of flashing smiley. I know that I'm supposed to stop testing at 9 days flashing smiley but I decided since it's after my D&C I'd go for it. Cheapies have been darker and darker and this evening I got a solid smiley. I couldn't believe it so I used the same sample to try with a new holder and a regular clearblue. Both were negative. Should I trust the solid smiley??????