How do you find way to tell if a property exists or not without using a try catch?

I am running a program to retrieve the "date taken" property of an image. The code I have found is mostly from StackOverflow. I am having difficulty with images that do not have a date. I have found that most images do not have a date in fact.

Anyway, the only way I can get the program to run without errors if the date does not exist is by the use of a try/ catch. I feel this is a very bad usage of the try/ catch facility and to make it even worse this is part of a project that will be graded. I do not think the marker will be impressed with it like that!

This is the code:

try
{
    Image img = Image.FromFile(imageFilePath);
    PropertyItem propItem = img.GetPropertyItem(36867);
    DateTime dTaken;
    string sDate = Encoding.UTF8.GetString(propItem.Value).Trim();
    string secondHalf = sDate.Substring(sDate.IndexOf(" "), (sDate.Length - sDate.IndexOf(" ")));
    string firstHalf = sDate.Substring(0, 10);
    firstHalf = firstHalf.Replace(":", "-");
    sDate = firstHalf + secondHalf;
    dTaken = DateTime.Parse(sDate);
    string dateConvert = String.Format("{0:dd MMM yy}", dTaken);

    dateTakenTextBox.Text = Convert.ToString(dateConvert);
}
catch (ArgumentException)
{
    //date does not exist so just carry on
}

All I need to do is just verify that the property actually exists. The exception is thrown on the second line of the main code section: PropertyItem propItem = img.GetPropertyItem(36867); I cannot work out how to detect that before the error actually occurs.