Suggest Remedy For Getting Sterilised

Hi im 27years old ill be 28 in July i have 3kids and would like to know what is the likely hood of me be able to be sterlised? Both myself and my husband have chatted about this and i have done all the research and i seriously dont want anymore children. I suffer from POC and hardly have any periods. I was put on the mini pill and another pill but both made me bleed the whole time i was taking them please help. Georgina