Previous potential head injuries.

Hi a few years ago I fell and hit the back of my head while out drinking. I did not lose consciousness or any after effects that I can remember. Also about 5 years ago u was attacked and fell back and hit my head at the back. Again I was out drinking and didn't think I lost consciousness. The paramedics dud advice me to go to the hospital but I felt ok at the time and signed the forms to say I refused hospital treatment. For about a week after my one eye I couldn't open as it was sensitive to light but I thought that was from getting punched in the eye. I have recently started mixed martial arts and a friend of mine brought up the topic the otherday and said it would be wise to speak to someone. Would i have seen the effects from these incidents if something was wrong by now and would it be wise to speak to my doctor?