I got my mirena (levonorgestrel) out a nonth ago and switched that day to nuvaring. when should i start bleeding again? breakthrough hasn't started, none after removal

1-2 months: Mirena (levonorgestrel) inhibits the growth inside the uterus and it takes a little time to grow back. With the NuvaRing you will probable have a cycle by the time you remove the second one. That assumes you use it cyclic, 3 weeks in 1 week out. If you immed. Started using continuous, 4 weeks in and immed. Switch with a new one, you may not have a cycle.