I have two hard lumps at the side of my right breast still, I'm 5 months post breast reduction.

I strongly feel that the lumps are a blood clot ( about the size of a golf ball maybe a bit bigger) Can you please tell me what is the best course of action to confirm if this is the case, do I need an x-ray? Do I need surgery to remove it? Or will it stay there & dissolve for its self? Can it cause me any further complications to my health or healing process? Can I fly long haul flights in the time being? I would really appreciate some professional advice, Thanks.