I dislocated my finger two days ago and straight away I 'popped' it back into place; its swollen, bruised, it hurts/aches do I need to see a doctor?

Depends. If it moves well and does not appear rotated, you will likely end up with the same result whether you see an orthopedic surgeon or not. However, you will get help with improving stiffness and predicting the final outcome.
Yes. The sooner the better. Not uncommon to developed lesion of the ligaments and tendons after injuries than can cause deformities and loss of function.