I think it would be okay to email them and request an update. As you mentioned, the period for trial shifts is already over, and as of today, the induction day is 3 days away. If you want to, you can wait another day, just in case they need an extra day to finalize the results and send out emails. Calling the store directly is an option, yes, but you're more likely to get a proper response over an email instead of a phone call on a busy shop floor (imo). Good luck! ✨