Krisvee - I have had the opposite experience. I think because I always get up to wee in the early hours so my fmu is not particularly concentrated. Weith this baby I did a hpt in the morning and it was bfn - well there could have been a line ifykwim??? In the afternoon after not drinking for 4 hours and holding my bladder it was a clear bfp albiet feint.

It all depends on the concentration of your urine. Your FMU shouldbe more concentrated but if you are a nocturnal urinator! than it may not be...