Period late

I am two days late for my period. I am extremely anxious and scared. I took a pregnancy test and it was negative. I do feel this fullness in my uterus and occasionally ill feel this ripping feeling inside like the wall is ripping off that lasts just a few seconds. could that be like cramps? i never felt that before. I did have an abortion about three months ago, and have had normal periods in between. im very nervous now. I have no boob soreness which is my one sign of my period I usually have. im very stressed and scared please help.