Stupid Sexing Question

I have 6 plants and I have confirmed that 5 are female. The last one is a tall sativa and its been 2 weeks since I began flowering and I can't tell what the hell it is! I would take a picture, but there really isn't much to show. I know what pollen sacs are suppose to look like but this plant isn't showing much of anything! I guess my question is can some plants take longer than 2 weeks to show sex? I'm baffled.

Different strains mature at differnt rates. You will just have to be patient.