Braces removed: I won't be able to get my retainers until a month from now.

Hi there,
the simple answer is: YES.  You should be very worried.  It does not matter how stable the result is after orthodontic treatment, all orthodontic cases have a tendency to relapse, especially in the first 2-4 months when the ligament around the tooth recovers and the bone around the teeth hardens.  This is the most crucial time after your brace removal and you must have an adequate retention protocol otherwise all your efforts may end up being wasted.
If you have a bonded wire retainer at the back of the teeth then the matter is less pressing, but you still need to have a retainer within a week or so to keep the rest of the teeth from moving, as bonded retainers only retain the front six teeth and not all orthodontists are in the habit of placing them.
I would endeavour to go back to your orthodontist straight away to get your retainer (my patients get theirs the day after, at the most 3 days) and if this is not possible you may need to seek an alternative orthodontist to provide you with a retainer sooner.  It would be a real shame if the ortho's hard work and your dedication were wasted.
Hope this helps!
Best,
MJ x

That sounds very strange that you wouldn't be receiving your retainer for a month after having your braces removed.  In our office, we try to deliver the retainers the same day, although sometimes we will deliver it the next day.  I know some offices deliver the retainer a few days out as it can take some time to have an outside lab fabricate the retainer, but a month out in my opinion is way too long and it is possible to get some shifting of your teeth in that time.  I would ask your orthodontist why it will take that long to get your retainers.