The other day I noticed that my laminate flooring was swollen below one side of my french doors, leading me to believe that water is getting in. Both doors are operable and swing in. The doors do have an adjustable threshold. When shutting the doors, you do have to push firmly because of the tight seal, so I'm not sure the threshold is the issue. However, when it rains the adjusting part of the threshold is wet when I open the door, which I don't think it should be being that the seal should cover it. I opened both doors today and noticed that at the hinge area of the left door there was staining from water. This is the same area where the flooring is swollen. I have never seen any water on top of the flooring or leaking through even during rain. It's underneath. Yes there is flashing all the way around the door. I installed gutters above the door today hoping that it would help keep water off the door sill. Any help and or suggestions would be appreciated. Thank you.

Gutter should help but what is the surface immediately outside the door? If it is a patio, does the patio slope down away from the house?
Also, check for problems inside below the door. Comments based on my experience with a similar situation and finding serious problems with joists below the door, all caused by a patio built level instead of sloped away from the house. Good luck.