Girls, have you ever had this happen? I found head lice at the beginn…

Girls, have you ever had this happen? I found head lice at the beginning of my pregnancy. The house is clean, everything is tidy and in the family everyone bathes every day and cleanliness is observed. In childhood I've never seen anything like it. The children don't have any and neither does the husband, but I have them on the back of my head. What could be causing this? And how can I get rid of it if I'm pregnant?