I had a missed miscarriage and they gave me 4 vaginal pills two days ago, when is the pain going to end?

Sorry about loss: It is not uncommon to use a medication called Misoprostol to aid in the expulsion of a miscarriage. This is most likely what you were given. It often works in as little as 2-3 days. If you are in a significant amount of pain, though, you need to call your doctor immediately. Hopefully an ultrasound confirmed a pregnancy in the uterus.