I am getting a sharp pain in my lower left abdomen. It comes in waves and subsides after sometime. I also feel nauseated almost the whole day ( this is from the past 2 weeks) and sometimes burning sensation in and around my digestive tract. I am also feeling completely drained out. We are trying to conceive but I have taken a test and it was negative. I also have mild PCOS and get my periods in around 50 days. What could be the reason for the change in my health?