How safe is it for one to take with uterine fibroid to take fish oil a day?

Safe. Entirely safe. I suppose fish oil can make you bleed easier but i cannot imagine that it can cause any great problem for you.
You're fine. I'll let you and other people decide whether fish oil actually does you any good; be sure you have an objective, unbiased review including the new work on fish oil and atherosclerosis. Having a fibroid is no reason not to take it.