period and pregnant?

Could I get my period then be pregnant? I had protected sex when my period ended. 4 weeks later, I got my period. Could I still be pregnant even if I got my period? 
I lost my virginity in April and I got my period in May but waiting for my period this month. I'm kinda new at this so I'm not guaranteed I'm not pregnant unless I get my period this month. Took a test last week to calm myself and it was negative.