I don't accept doctor's notes.  If you're not at work, you're negatively impacting the business.  If you have a good attendance record and something happens that causes you to miss some time from work, big deal.  If you have a terrible attendance record and you bring in a doctor's note, well, you should have made a better effort to be at work the other times you called out.   With that being said, every scenario is unique and each one it looked at on a case-by-case basis. 
Being a new TM makes it difficult.  There is no one-size-fits-all solution to this problem.  The best thing you can do is call your store and explain the situation.  I doubt you'll get fired,  but if you have any more attendance issues within your first 90-days, that could pose a problem.