Ah that explains why it didn't swell, I needed to put it outside and not back in the fridge. I thought I didn't smack it hard it enough.
It turned out okay though b/c something came up and I couldn't brew so just am going to leave it in there until tomorrow or Saturday.
Are airlocks required for yeast starters. I have a flask but it came with foam stoppers. Can I pitch yeast into the flask w/DME and just plug the foam stopper on?