Functional cysts?!?

Cassandra • -Son born 5/9/13 -Daughter born 8/16/15 -currently pregnant w/baby #3 (girl)
Thursday the 30th I had serve pains on right side it started 2 days before but gradually got to the point it was hard to walk. Talked on phone w OB dr he said sounds like a functional cyst
Now 8dpo and as of yesterday started having cramps/pains on right side again. Worried something is wrong  made an appt to be seen today
Am I over reacting? 
Any idea what it could be?