Why am I cramping

Aa

Hi ladies I’m due my period on the 16th but now I’m cramping mad like period cramps this is happening on and off sense the last 3 days does anyone have idea what this is my ovulation day off the 1/2nd January my widow week stared from the 28th December and we baby dance almost every night expect On or 2 more nights but always closer to the day we did it more