I was diagnosed with ovarian cancer stage 2 last year. i had persistent cough this month and had an xray it showed that there is ipsilateral effusion?

Need more testing: The fluid should be drained ( if big enough) and sent for laboratory and pathologic analysis to determine its nature. You will also need restating ct scans and recheck tumor markers ( ca 125).

Fluid one side: An ipsilateral effusion means there is fluid on one side of the chest, the same side as (something else, no clear here; same side as the ovary or a concomitant infiltrate on the lung?). This can be caused by things like pneumonia, if your symptoms are consistent, but also from metastasis; discuss this with your cancer doctor, you may need the fluid tapped for examination.