The kind of mindset that you would be in post breakup is most likely not going to be all that rational, and it is important to note that acting on any and all impulses that might come to you while you are in this headspace would not be wise to any extent whatsoever regardless of what your internal monologue might be attempting to convince you of. For example, you might be thinking that you need to try to get back with your ex as soon as possible, but in spite of the fact that this is the case acting rashly in this regard is actually going to make it less likely that she would ever want to take you back at the end of the day.
If you think that impressing your ex and having her take you back is even remotely a possibility so soon after your breakup then you are sorely mistaken. The thing is, if your breakup occurred during a fight then it is really important for you to give your ex at least a little bit of space so that they can breathe a little and cool off.
Trying to talk to them while they are still in an angry mindset is just going to turn them against you even more, and suffice it to say that that is not going to be good for you down the line. Just give them some space and let them get in touch with you for at least a week. If a week passes and they still have not gotten in touch, you can talk to them safely without arousing any negative emotions at all.