Words are easy, especially after a breakup.
What matters more is what happens afterwards. If an ex genuinely regrets their decision, they may try to have a meaningful conversation, address old problems or make a consistent effort to rebuild trust.
That is very different from sending an emotional message at midnight and disappearing the next day.
Still, there is an important difference between regret and wanting to reconcile. Someone can miss the relationship, feel guilty about how it ended or realise your value without necessarily being ready to build a healthy relationship again.
So rather than reading too much into one text, one call or one social media interaction, look at the pattern. Consistency usually tells you much more than a sudden emotional moment.