Are all the sentences very natural for the context?

A friend of mine has missed the last few weekly appointments with me, so I call and ask him why he wasn't there this time. He says he's just forgot about it. I don't expect to see him next week either but I ask him anyway:

1) So you're coming next week?

2) So you're still coming next week?

3) So you're going to come next week?

4) So you're still going to come next week?

Are all the sentences above very natural for the context? Which one do you think is the better one for the context?