light period

Ma
Hey guys so all day today I had cramps, and usually when I start my period they are really bad like so bad that I need to get in a warm bath. But today it wasn't bad at all and it was very light and dark brown. And I'm usually really heavy, I have had sex but I'm pretty sure I'm not pregnant because I haven't had any symptoms but I'm waiting a couple days to see if my period gets heavier. I'm never regular so I'm assuming my period is light and tomorrow it will be heavy just thought I asked and see if anyone has had the same problem!