Ranked Safety Net

I recently just went from Unranked to Silver I. After my promos, I proceeded to lose three games. I've read online that you get three games where you won't go down a rank if you lose, and if you win the safety net disappears and you start to gain/lose LP. However, my plat friend and another post I saw stated that you can lose as much as you want, as long as your MMR doesn't go too far below what it's supposed to be. I'm very nervous, as I don't want to go for another match and lose, but at the same time I want to make an attempt at Gold V before the season ends. Thanks