Forex Usual small momentum reversals at 45 minutes, Why?

This might have been bought up before, but I have noticed something on almost every trade I've done.

Let's say a price has been bullish from the beginning of an hour. Nine times out of ten, I've noticed that between the 45 minute and 58 minute mark the price will go in a bearish direction, before the momentum continues in the last minute or two and the candle finishes bullish. This happens on both long and short positions (but just the other way around obviously).

Does this actually happen or is it all in my head?! If so, what causes it?

Source.