Yes, it could be coincidence to see a series of clock times, each entirely composed of the same digit.

If you keep wondering about it, though, it may happen more frequently. The subconscious seems to direct attention toward things related to what a person feels need to be solved.

If it's just the one night, probably it's coincidence.

If it continues, it might be your subconscious waking you up at those times. Or there might be a special significance.

Here's a link to an article with links to even more articles that may help you determine whether or not seeing the clock times has a significance for you: Index to 'Repetitively Seeing the Same Number' Articles

For reference, here is a short paragraph about the numerological meaning of the three clock times you mentioned.

11:11

The essence of the number 11 includes intuition, charisma, and spirituality. It is inclined toward both independence and teamwork, both aloneness and coexistence. With 11:11, the influence of 11 is doubled, and also includes the vibrations of focus, method, and pragmatism.

4:44

The essence of the number 4 includes focus, conscientiousness, method, and foundation. The essence of the number 44 includes efficiency, focus, and building things to last for generations. With 4:44, the essence of both 4 and 44 are merged, with the vibrations of creative self-expression, tolerance, and inspiration included.

5:55

The essence of the number 5 includes expression of personal freedom, sensuality, wit, and adventure. The essence of the number 55 includes independence, adventure, and self-determination. With 5:55, the essence of both 5 and 55 are merged, with the vibrations of family, harmony, and idealism included.

The only common number in the major positions of your numerology chart is the heart's desire number 5.

I hope the information is helpful.