Disclaimer: MD here
At this stage, 3 months post injury, if it was a haematoma it is now likely to be a well organized clot that you cannot aspirate easily to get rid of it.
In this scenario it is likely to be with you for some time. You can try putting a needle and syringe in it yourself to see if anything can be aspirated from it. If not then a minor procedure using local anaesthetic is all that is generally required. I would get an ultrasound of it before hand to confirm what you are dealing with.
You have not said where is it or whether you have any bleeding disorders or if you are on any blood thinners. This is important for a number of reasons.

not on any medications or any bleeding disorders, it is on side of my hip.