Is this only talking about when you first begin the pill or all the time?

Because I’ve been on the pill for a year now and I’m a bit confused?

Do I need to take 7 pills in a row to be protected?

Because I just had sex last night and I had only taken three pills in a row because I had my period 3 days ago meaning I was only taking the sugar pills:

Someone please explain this to me and help me out!