Yes, you can wear your sports contact lenses while playing sports. Since you are nearsighted, you may in trouble of focusing something if you not wear the sports contact lenses or other prescription sports goggles. So, put in your sports contact lenses for better vision to do better in the sports.
When you are playing sports, you can wear your sports contact lenses, because the original aim of contact lenses are designed to sports. Generally speaking, in the normal sports, you can wear contact lenses, such as jogging, billiards, fitness, swimming. But when doing strenuous exercise, you'd better not wear contact lenses, because the contact lenses are easy to hurt your eyes.
Of course, you can! There is no danger. There are three advantages wearing contact lenses. First, the contact lenses may not be smoggy when you breathe deeply. Secondly, they can hardly be easy to fall down from your nose. Thirdly, they may be clearer than framed glasses when you see something. In a word, they can bring you more conveniences. Anymore, even with them you can still swim, just be careful about not opening your eyes underwater. I play water polo without goggles and I have contacts and I am fine. I swim all the time in mine without goggles, but I am very careful about opening my eyes.
It depends on what kind of sports you do. Like the jogging, tennis and fitness, it is safe to wear the sports contact lenses. However, you can not wear the sports contact lenses when you are playing fierce games, like the swimming, playing football, free combat and some other strenuous sports, especially swimming. Because the water in swimming pool is not so clean so that it is injurious to your sports contact lenses.