Scales Help

Well, I want to play around with this riff I wrote, and I am going to try some harmonizing to see how is sounds.

E---------------------------------------------------
B---------------------------------------------------
G-----2----3----2----3----2----3----5--3--2phb----
D-0-0--0-0--0-0--0-0--0-0--0-0--0-0---------------
A---------------------------------------------------
E---------------------------------------------------

(phb=pinch harmarmonic bend thingy)

E----------------------------------------------------
B----------------------------------------------------
G----------------------------------------------------
D-----2----3----2----3----2-----3----5--3--2phb----
A-0-0--0-0--0-0--0-0--0-0--0-0--0-0----------------
E----------------------------------------------------

Thing is............. I don't know what scale to use! Help! I have no idea what scale it is in, just a random riff.

(Yeah! I have no idea about songwriting)

You can use A Phrygian (thats the "same" as F major)