what's does a MC feel look like?

So I am 4w 5d . This is my first pregnancy. I know we all want to be optimistic and put away any  bad thoughts but I can't help be cautious and vigilant. 
What does it feel like to have a MC. I know we are all still very early so I wonder .  Would one have cramps , bleeding or nothing at all and find out at the first ultrasound?