HELP!!!

Since 7 DPO I've had mild cramping on and off I'm not supposed to get my period until the 31st I'm always on time or a couple days late and I don't usually get cramps until the day of my period. What could it be?

I'm scared I might be pregnant I have a nine month old baby and have been getting my period since 2 months after I had him I don't know if I'm ready for another one.