I have mirana and i need Iud help anyone?

I got mirana last year in July and i think something might be wrong. I have been really bitchy and very irritable and moody, i don't have bloating and i know i should use condom with my boy but we don't, and every time i take a test its neg. but i don't want to go waste the time?? what do people think i mean i was told that 97% of girls on this don't get there period, and i did.. Also i herd that 1 in 1,000 get prego. but i ready a lot of this about girls getting preog. on this?? What do i do??