Do not go by brand names or sizes when selecting your cycling shorts. Find one that fits you most comfortably. Ideally, you should try the shorts before buying them. This is important because each brand has its own styling. You need one that does not restrict your leg movements or put pressure on your waist or crotch.
You should also ensure that the sorts don’t cut deeply into your body or affect your breathing. Another point to check is their fit. If they are too tight they will rub against your skin, and cause constant irritation. This may even lead to the development of sores.