might be pregnant again

Started having sex at week four (unprotected) we've been pulling out. I'm now on week six. 
First things first when the heck do I start my period again && how would I know if I got pregnant again ! When can I test to see 
Update: yes I bled and had cramps after. 
Now it's clear discharge
How do I know when my period is due and when can I test?
With my other one I tested two weeks after sex with a positive result