It's a good idea, fish oil is also very good for heart health, we should all be taking it. You will want a good fish oil with a good EPA / DHA ratio. 2–3 g/day combined EPA + DHA - Note that your average 1,000 mg fish oil capsule often contains only 300 mg EPA + DHA.
This is why it's common to see fish oil in peoples AM and PM supplement routines. I personally take 4 in the morning, 4 in the evening before bed with my zinc etc.
Other things you can add would be Collagen peptides / Vitamin C, Curcumin and Glucosamine. If my joints are playing up it's typically 1) I need to deload, 2) the Winny is doing its thing or 3) I've fucked up and have crashed my E2.