Pregnant?

I'm 18 years old and for as long as I could remember, my period has been irregular. Just the last couple months my cycle length has been consistent at 22 days, but it is still a short cycle. The first day of my cycle was July 21st My bf and i had unprotected sex on August 1st, day 12 of the cycle (two days after my period ended). I haven't gotten my period since.