My stomach is constantly growling.... how do I stop it?

I'm a healthy 15-year-old female. In the last couple of weeks, my stomach has started grumbling very loudly, it has also been accompanied by a feeling of hunger. It is very loud and embarrassing especially in class, and it is putting me off work. It is strange because I will feel hungry and my stomach will growl, so I eat something so it stops, for only a few moments. It is not because I am hungry, as I will have a large dinner and I will feel hungry and my stomach will growl only 5 minutes later.  It is a constant cycle and has started eating much more than I usually do, yet I have gone down in weight from 52.7kg to 51 kg, in only two weeks. 

It is very loud and constant! I don't notice it much when I'm home because I don't worry if people can hear it. 

I need some urgent help to stop it because I have exams coming up and they are around 2 hours long each, in a hall, in silence, with the rest of the year group.

Please help me!

Hi kate when last u had a clean out as in worm meds? Chk a see an ask your doc to prescribe