I had a scraped knee 2 weeks ago in mexico that was a bit infected. i now have 1 pea size swollen lymph node(femoral groin). could they be related?

They are related: Many cutaneous infections tht could arise from a scraped knee resulting even in a minor inflammatory response can result in spread of the superficial infection. This would occur via spread up the superficial lymphatics to reach the groin. The result would be a slightly enlarged node. Warm soaks to knee and groin could help by drawing in blood supply and result in some drgree of resolution.