I think it makes sense to look for a schedule with 7 weeks where all teams play each other exactly twice. Perhaps the following would work for you where the 7 teams are A to G:
630pm 730pm 830pm
Field 1 (B F) (A D) (C E)
Field 2 (A C) (B G) (D F)
-------------------------
Field 1 (C D) (F G) (A E)
Field 2 (E F) (B D) (C G)
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Field 1 (D E) (B C) (A G)
Field 2 (A B) (E G) (C F)
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Field 1 (B E) (D G) (A F)
Field 2 (A D) (E F) (C G)
-------------------------
Field 1 (A B) (C F) (D G)
Field 2 (C D) (A E) (B F)
-------------------------
Field 1 (F G) (B E) (A C)
Field 2 (B D) (A F) (E G)
-------------------------
Field 1 (B G) (C E) (D F)
Field 2 (D E) (A G) (B C)
