One of the challenges of public speaking is timing your talk. And paying attention to that timing without distracting your audience.
Do not mention the time to the audience.
Do not say you only have 5 minutes.
Do not say you won’t take up too much of their time.
Do not point out you finished with one minute left.
Do not mention you are running a couple of minutes over.
Do not ask for a time check.
If you focus your audience’s attention on time, they will think about time, instead of the topic you’d like them to be thinking about.
The one exception is if someone is waving a huge placard saying you have 5 minutes left, distracting both you and the audience. In that case, nod to acknowledge them and go on with your talk.
You should focus on leaving your audience with one key message. And that message should not be how you are delivering your presentation unless your talk is about presenting!