Lice…

I am a teacher, I have had one student that has had lice this week and was sent home. Now a paraprofessional who works in my room went home for lice and another teacher who works in my room also found lice in her hair tonight…. I’m paranoid. I had my husband check when I got home he didn’t see anything live. Then I showered and used a tea tree oil shampoo. After my shower I brushed through my hair in individual chunks, starting at the roots. My husband checked again and didn’t see anything like eggs. Should I be good with the measures I have taken????