Can fly bites cause sore muscles?

Yesterday i was at the tennis courts and i remember a fly biting me, when i tried to kill it, it flew off my leg. Then it just kept coming back to pester me. This morning I woke up will muscle cramps on my legs, thighs, and hands. (usually near joints). I could not go to tennis practice because of it. I dont know but it seems like my muscles are swollen and the area i remember being bitten is swollen too like a mosquito bite and i dont even remember scratching! Are there any flies in NJ that can cause this? and if so, and treatments??