It's possible/manageable to have 2-3 anecdotes in one discursive piece, however it depends on how many words in total (if you have a word limit) you are allowed to write and can write under exam conditions.
One anecdote may be better though if you think the one personal experience conveys your idea/purpose effectively and holds more importance, than having multiple examples of your discursive's purpose through the detailing of personal anecdotes. It's also good to consider only including 1 anecdote, especially if this anecdote it quite large/long in words