So I guess I'm confused because I keep reading posts from people saying that they hit their heads again and it causes the PCS symptoms to return. What I'm wondering is, how do you know it isn't another concussion? If you hit your head and doing so results in concussive symptoms, how would you really know if it were just PCS symptoms or an actual concussion?

Maybe I'm just a little overly sensitive lately. I hit my head again yesterday and have had a headache, slightly blurred vision and have been seeing spots sporadically ever since. Now I have to decide if I need to waste my time at the emergency room for them to tell me I have a 7th concussion or tell me its nothing. Really though, how are you going to know for sure unless you get checked out?

As I said, I'm wondering if I'm just being overly cautious. My aunt passed away last month from a subdural hemorrhage and I'm just nervous.

If you have a dangerous condition, it will be evident. You will have one or more of the following:
excruciating head ache
a difference between functions on the right side versus your left side
Loss of muscle control
vomiting and extreme nausea
extreme sleepiness
and a few other extreme symptoms or loss of function

If one of these symptoms shows up rapidly, get to the ER.

Otherwise, you have either suffered another generic concussion or caused your previous concussion to be aggravated.

You deal with the symptoms, not a specific diagnosis of cause.