Two periods on Jan

I had my period on 1st Jan,2019 till the 7th and last week I was super sick, I was so tired I couldn’t get out of bed, I didn’t have fever but I had headache and running nose. I went to the doctors and got some medicine but prior to this I already had back pain which I thought was weird because I already had my period...Then suddenly yesterday, I started my period which I would have understand if my period this month was light but it was heavy and today it’s medium. I tracked down to see if there’s any insight on why I have 2 periods this month, I got none so far. Can anyone help me on this topic? Thank you in advance!