Two periods in one month ?

I don’t know how to start this but I just had my period not too long ago, and today I had sex with my boyfriend but then next thing I know blood comes out. Like period blood. I got kinda worried that I was bleeding so we stopped. So I showered and started to think and asked myself “is it possible to have two periods in one month?” Now I’m not scared but I am worried, because I know I just had my period for December but why is it coming a second time around.

•If anyone could help me out and figure out if it’s normal and okay to have two periods in one month?