What Is The Solution For Sharp Cramps In Uterus Area And Back After Undergoing Spontaneous Abortion?

I have been having some cramps...that feel like a sharp knife in uterus...this started over a week ago. I have been having horrible lower back pain but it feels like in my female organs. I missed my period yesterday! What do you think is wrong with me. It is normal for me to get pregnant and have a spontaneous abortion with my period but I haven't felt pains like this that is prolonged!