Flu like symptoms - New to Metformin.

Hi

I have type 2 and have just started taking metformin, I am on 1 500mg tablet per day for this next month, I started taking them 4 days ago.

Today I have woken up and feel like I have the flu, my throat is sore and my arms, legs and neck are aching.

Is this just a side effect of metformin?

Thank you.