CEFALEXIN IS SAFE?

TWO MONTHS PREGNANT NOW. SUMASAKIT LANG ANG PUSON KO THAT TIME PERO KINABUKASAN NAMAN NAWALA NA, SABI KASI SA CENTER, PRESCRIBED ME TO TAKE IN CEFALEXIN 3X A DAY FOR 7 DAYS. IM WORRIED BECAUSE ITS ANTIBIOTIC, IS IT SAFE FOR MY BABY? AND BY THE WAY, IS CEFALEXIN 500MG AND CEPHALEXIN THE SAME?