I think you can start taking them a few weeks before, I believe it's recommended if you're expecting a c-section. I only started taking them after because I hadn't really heard of arnica before my section. I think the cream is really working as my wound is just an incision line now, no scabby bits or redness anymore. It's not even been five weeks yet so I think this is good progress.
I don't think there's any right or wrong time to start taking it, so I guess it's up to you!! xx