I am 17 and have missed 2 periods. I have also been experiencing abdominal pain which has been getting worse, also i have had stomach cramps.
I have been to the doctors have had 2 pregnancy tests done which have come back negitive. A water infection test was also done which came back negitive and also Sexually transmitted disease swabs and they all came back fine.
I am sexually active and dont use any contraception.

Can you please help me work out what is wrong ? ?