Hi, I Had Unprotected Sex On The 24th March, But

Hi, i had unprotected sex on the 24th March, but i went on my period normal and it lasted 7 days as per normal and normal flow. On my last day i decided to be on birth control (Petogen 2 months). just after i got it i took home pregnancy text to be sure. But since i have been having terrible headaches, very moody, and feeling very bloated, cant even sleep on my tummy, also i kinda have cramps as if am going on period again. Could i be pregnant or its side effect of the birthcontrol?