I had a tooth extraction 3 months ago, from a cracked abcessed tooth i'm still getting pains occasionaly, could this mean the infection is still there?

Possibly: If you are still having issues after 3 months you certainly need to see the dentist that removed the tooth. It could be secondary infection, it could be a small portion of the root was left in place(there are reasons we sometimes must do that) or it could be slight nerve damage. Without seeing a current x-ray, which should be included as part of standard follow up at this point, it is hard to say.

Have it checked: It may or may not be an infection but usually the pain should be resolved by 3 months. Doesn't hurt to take another radiograph to make sure everything is ok and all the pieces of the tooth are out.

Extraction pain: The pain after a tooth extraction is normal up to about 2 months. After that it could be something else. Possible causes of pain are a tooth next to the extraction and referred pain, a possible bone spur, or possible root tip left in the bone, possibly a dehesence meaning a hole in the tissue exposing the bone. You should have it looked at.