Yes, you can drink sweet melon during pregnancy. It is said to avoid these fruits like sweet melon, bananas, grapes and mango during pregnancy as these fruits contain high calories. But if you take these fruits in moderate quantity then it will not harm you. You must take all these fruits as you like as these fruits will provide you energy and they are also not very high in calories, so that you should avoid them. If you are pregnant then you must eat all the things as per requirement of your body as your mind is not in control in this condition.