Yes, both moped riders and cyclists are allowed to overtake you on both the left and right side. This means that a cyclist or moped rider may suddenly appear next to you, or just behind you. The risks associated with this are greatest when you turn in densely built-up areas with a lot of traffic.
Remember that you must always check your rear-view mirror and side mirrors as well as your vehicle's blind spot by briefly glancing over your shoulder before turning, moving your car sideways or reversing.