Bloating and cramping are what doctors term as "vague" symptoms as they do not specifically point to any particular organ or structure in the body, yet sometimes these can be the first signs of something more serious happening within the body.
For a younger person, female, like yourself, it very often could be due to hormonal changes or fluctuations during the menstrual cycle. Some are associated with "premenstrual symptoms" such as headaches, mood change, feeling of water retention, or even acne outbreaks.
However, as mentioned earlier, sometimes these symptoms could be due to other medical conditions, such as endometriosis, or growths within the pelvis such as ovarian cysts.
If the symptoms are persistent or worsening, it may be a good idea to get an ultrasound scan of the pelvis (which is easy to perform).
Best regards
Dr YF Fong