Hello,
I am a 22 year old and I ALWAYS have a 28 day cycle. Last month (October) I came on, on the 22nd and it lasted 5-6 days (which is normal) this month I had unprotected sex on the 7 (which was the 17th day of my cycle) and then had my period on the 18th BUT it was only 4days (but still normal flow) Today is the 23rd and I am cramping, Could this all be signs of early pregnancy? How long should I wait to take a test?

Those are not typical signs of early pregnancy.

I suggest waiting a few more days to take a test to be sure. Its possible the cramping you felt today is your body preparing to ovulate or its something else entirely. Of course, its hard to say over the Internet. ;)