HI. I am sorry you are going through this.
You don't say how many weeks you are? I had a miscarriage at 13 weeks when baby had stopped growing at 5 weeks.
The pain is quite bad, bad enough for me to take to my bed. Much like early labour, it comes in waves of contractions. This lasted from first grumblings at 6am through to 11am for me - so 5 hours.
It is scary and frightening, but if you are prepared and know what to expect, this is much easier to deal with alone.
I will be honest here, so please don't read on if squeamish or if you'd rather not know - but there will be a lot of blood. A real lot. To the point where I worried I needed to go to hospital due to blood loss.
I would recommend getting yourself set up and ready for the night ahead.
Get all the towels in your house and lay them next to your bed. Put a couple of folded towels under you and expect to need to change these towels several times over the next few hours as they soak through with blood. Just throw the used towels on the floor for now.
Try not to get up until the contraction pains finish, just rest. I felt lightheaded when I first stood, due to blood loss.
You may also get some 'whooshing' blood come out when you sit on the toilet. I kept on bleeding heavily for 3 more hours after the contractions finished. Blood would pool if I lay down for too long, and there was large gushes of blood when gravity kicked in when standing.
It is a horrible, horrible thing to go through. But IMO better done in the caring, comforting environment of your home rather than a hospital filled with over-worked staff.