Hello everyone! I haven't posted here before but I have been lurking for awhile. I am a SAHM to an awesome little girl who just turned 1 on the 21st of December. DH and I are ready for #2 so I started using OPKs. I used them with DD and we conceived in 2 short months! I have never used the digital before and Walmart was out of the others. I took one yesterday and got my smiley face but I didn't trust it (I was thinking O wouldn't be until Thursday but I know this can change) so I waited 4 hours and took another and it was negative. We went to town today and they had the others so I bought them and the line is darker than the one I took before I started the digital (last time I used them they slowly got darker). I used a digital with the same urine and it was also negative. So my question is...is there such thing as a false positive OPK? My cycles have currently been 30-31 days since having DD.