So my miner was running pretty good at around 5.5MH/s earlier yesterday but I restarded it and now its running around 4.7 MH/s. Why is that? Nothing is wrong with the miner thats for sure. I'm using BFG miner and these are my settings.

Bfgminer -S gridseed:all --set-device gridseed:clock=850 --scrypt -o stratum.fast-pool.com:3002 -u name.2 -p x