If the stem isn't actually broken, then you're good. Even if it did break, as long as most of it is still attached then it will probably heal.
In the future, if you crack a stem or even break it off completely, then IMMEDIATELY reattach with tape. You can get gard tape, but even duct tape will do the trick. Give it a week and unwrap it to make sure it's healing. If it was a small crack you're probably good. If it was a big crack or complete break, then reapply the tape. The trick is to not re-tape it too tightly, because it will still want to grow and expand. Good luck!