Time for a change?

Ok so ive been on the pill since November of 2013, with that being said I have a few questions: 
1- Is it possible after a while you become almost immune to the pill after so long that the effects of the pill no longer work (i.e. Helping acne, stoping cramps, short periods)? Because in the last 2 months iv felt like iv gone back to square one when I first started. 
2- thinking about switching from pill to IUD. Any recommendations ?